I had been plotting my return to China for about a year, and now an invitation from Lanxin Xiang, author of a book on the Boxer rebellion, to lecture in Shanghai in September 2005 made it possible. I say "return," because the last time I had been on the mainland was in 1948, when I was nine years old. I was born in Harbin in Manchuria in 1939, came to England when I was three, and then went back to China with my parents in 1947, living for a little over a year in Tientsin (now Tianjin). We escaped to Hong Kong just before the communists took the city.

Why had we gone back to China in 1947? The brief answer is that the Skidelsky family owned large properties in Harbin, and leased the largest private coalmine in Manchuria—the Mulin Mining Company. After the second world war, my father, a British subject since 1930, decided to reclaim the family business. In a spectacular piece of bad timing, we reached Tientsin at the moment when the communists were seizing control of Manchuria from the nationalists. We hung around in Tientsin waiting for the reversal of fortune which never happened. I remember thinking even then what a bad general Chiang Kai-Shek was to allow his best army to be cut off in Manchuria.

When you are building your own life, your family history is a matter of supreme indifference. But now I am fascinated by my family origins, and wish I had listened more attentively to family stories told by my parents. They help me make sense of my own life. The Skidelskys were one of the leading Jewish-Russian families in the far east. My great-grandfather Leon Skidelsky started his career in Skidel, now in Belarus. At some point in the 1880s, he moved with his family to Odessa on the Black sea. In 1895 he won a contract—how and why I don't know—to build the last stretch of the Trans-Siberian railway, which ran through northern Manchuria to Vladivostok. Leon made Vladivostok the family home. The Skidelskys were one of ten Jewish families allowed to live there. My father, Boris, was born in Vladivostok in 1907.

By the time Leon died in 1916, the family owned residential, industrial and mining property in eastern Siberia, had 3,000 sq km of timber concessions in Russia and Manchuria, and was one of the region's largest employers. The Manchurian side of the business was managed from Harbin by one of Leon's sons, Solomon. The family firm supplied coal to the Chinese eastern railway (as the Manchurian stretch of the Trans-Siberian railway was known) and exported timber, plywood and flour to London and New York. The family has been identified as "oligarchs" of the far east in several recent books dealing with Russia's eastward expansion. As my host Lanxin Xiang told me, everyone in Manchuria had heard of the famous Xie Jie Si family—Skidelsky in Mandarin.

In 1918 the Skidelskys left Russia, losing all their properties there, but with several million dollars in cash. My father's widowed mother moved to Paris, and sent her four sons to English public schools. Back in Harbin, great-uncle Solomon acquired a 30-year lease of the Mulin Mining Company in 1924. This became the mainstay of the reduced, but still substantial, Skidelsky fortune. Harbin, already a big Russian city, swelled with White Russian exiles from eastern Siberia. The European sector was laid out with broad streets and avenues, fine houses, banks, shops, restaurants, cinemas, and an opera and ballet company. In the 1920s it was known as the "Paris of the east."

When my Paris grandmother lost her money in the stock market crash of 1929, she went to live in America and my father Boris went to Manchuria to work in the family business. He married my mother in 1936, and I was born three years later. My father fought for Britain during the war, but the Harbin Skidelskys, who were stateless, went on supplying coal to the railway, now taken over by the Japanese, who occupied Manchuria from 1932 to 1945. When the Soviets entered Manchuria in 1945, Solomon and his brother Simon were carted off to Russia, and perished in one of Stalin's gulags. The Chinese communists took over the Harbin properties and the coalmine. In 1984 I received a cheque from the British government for £24,000 in full settlement of a claim for compensation which amounted to £11m.

I know less about my mother's family, the Sapelkins, who unlike the Skidelskys were Christian Russians, but like the Skidelskys, were part of the eastern flight of Russians from the Bolshevik revolution. They were "free peasants" who emigrated from Nizhny-Novgorod on the Volga to eastern Siberia in the late 19th century, and were also involved with the building of the railway. My maternal grandfather, Veniamin Vassilievich, turns up as mayor of Manchouli, in Russian Manchuria, in the early 1920s, before moving to Harbin. He was a literary gent, and I remember as a child receiving a letter from him in very old-fashioned Russian (as my father told me in translating it), full of lofty moral guidance. My grandmother's family probably came from Bessarabia. My mother Gali was born in Harbin in 1918.

My family history is a microcosm of the first wave of globalisation—based on the railway, steamship and telegraph—which opened up east Asia to the world market over a century ago. The Skidelskys' rise and fall mirrors the fate of this cosmopolitan world, which was mortally wounded in the first world war. It shows how easily politics can capsize economics. Wealth did not save my family, and others like them, from revolution, nor did economic interdependence save the world from fascism and communism. Today there are no Skidelskys left in the far east. Following the communist victory in 1949, China was closed off to the rest of the world for 40 years. Harbin, together with ports like Shanghai and Tientsin, became a purely Chinese city, filled with the melancholy ruins of a dead European culture: the Bund in Shanghai, Victoria Park Avenue in Tientsin, the Bolshoi Prospekt in Harbin. Now a "second opening" is taking place. It is home-grown, but the European underlay is also unfreezing. In my birthplace, Harbin, I was welcomed back like a long-lost son.

19th September, Shanghai Lanxin Xiang (pronounced Lanshin Shang) meets me in the morning at Shanghai international airport, a spectacular structure. He is accompanied by a cameraman, Yang Mei, and a producer, Han Yu. My visit is to be filmed and shown on Chinese television. A bouquet of flowers is placed in my hands, and the cameras start whirring. We pile into a minivan for the drive into Shanghai. On the way we pass through the new city of Pudong. Ten years ago this was fields; it is now home to 4m people, with high rise after high rise of offices and municipal housing. I am staying in the Jin Jiang hotel, where Nixon stayed on his historic visit in 1972. Yang Mei's camera is running the whole time. I think he would take up residence in my bedroom if I let him.

I resist boiled toad for lunch, but I am looking forward to Chinese food. Lanxin introduces me to a Chinese vodka made of fermented rice. It smells of drains.

Walked down Huai Hai, the main shopping thoroughfare, formerly Avenue Joffre. A pretty Chinese graduate student, Qiujun Zhou, has been detailed to show me around—with Yang Mei and Han Yu she makes up my trusty team of three companions. Displayed on the pavement is a small green car, made in China, and known as QQ. I'm told it costs about 25,000 yuan, or $3,000. It is my first exposure to the "China price." I try to learn a couple of phrases: zhe zhe (thank you), Sia oo how (good afternoon), Kung kow shing tao chung kuo (I am very happy to be in…). Qiujun tells me to pronounce her name "children"—as the Chinese say it, without the "l" "chowjun." I'm told my accent is good, but my memory is leaky.

20th September, Shanghai Lecture at the Shanghai Academy of Sciences on globalisation. "How long am I expected to talk?" I ask Qiujun. "Two hours," she says. Fortunately she means the total meeting time. Lunch is formal—with a lot of professors. I get into a discussion with one of them, Zhou Jianming, about Taiwan. Would the US defend it against a Chinese invasion if it declared independence? He was certain it would not; I said it might. Accompanied by Qiujun, I visit a bespoke tailor Baroman and order a suit and jacket. They will cost 4,370 yuan or about $500.

21st September, Shanghai A morning visit to Dulwich College, the Chinese outpost of the south London school, in Pudong. Drive past miles of skyscrapers. How strict is censorship? I ask Zhang Shumei, a student who is accompanying me today. "You can discuss everything in public, but not criticise the government… that you must do in private," she adds. I wanted to see Dulwich because Brighton College, the independent school whose governors I chair, is thinking of opening a school in Russia. I discover that all the pupils are expatriates; Chinese nationals cannot send their children there. Why is this? I ask. The Chinese want to protect their national identity, so they won't allow anyone to be educated by foreigners unless they are already foreign. But they allow their children to study abroad? Yes, it's illogical…

Get back to Shanghai in time for a meeting with Yang Jiemian, deputy director of the Shanghai Institute of International Studies. He tells me that China is the status quo power, the US the revolutionary power. International law can be changed only by agreement, not by US unilateralism. As a Marxist, he believes that the superstructure will change with the base, therefore democratisation in China is inevitable, but it will be slow, and everyone must be patient. China is a "socialist developing economy." Socialism is needed to counteract what capitalism creates. Economic development increases inequality, socialist planning will be necessary later to close the gap. Is he allowed to tell the truth in public? He replies that when he can't tell the truth, he doesn't lie, but simply keeps away from the subject. He told me he was sent to be re-educated in a village in Mao's cultural revolution, and I can see that he is not going to take the risk of having to go on his travels again. He is skilled in rationalising leadership policies in language acceptable to the west.

It is 4pm and my three companions and I have got caught in a thunderstorm on the Bund—the old European business centre—with torrential rain, thunder, lightning. We take shelter at M, the famous restaurant. I am not allowed to buy the drinks. I did, however, buy a suitcase with my own money. It cost 100 yuan ($12). I notice that Mao's head is still on the currency, although he died 30 years ago.

22nd September, Shanghai In the morning I visit the old town of Zhujiajiao. My main guide, Qiujun, was born there, and calls it the "Venice of China." In the courtyard of the restored Tao temple I see the symbol of yin-yang carved on a stone. The rejection of the spirit/matter, good/bad dualism is what makes Chinese thought, I am told, so different from western.

Afternoon lecture on Keynes and globalisation, hosted by the School of Advanced Studies. About 200 graduate students and teachers. It is a difficult topic, but an efficient interpreter translated highlights. This is followed by a colloquium on east and west with Liu Qiliang, a professor at Xiangtan University.

In the evening we take a cruise on the Huangpu river in the Great Dragon, with the skyline of the Bund on the west bank and the spectacular new Shanghai on the Pudong side. Some of the new architecture is both stunning and strange: the Pudong side is dominated by the television tower Oriental Pearl, a pencil reaching to the sky, with two great coloured orbs that change colour.

23rd September, Tianjin I am flying to Tianjin, where I lived in 1947-48, attending St Louis College, the French school, belonging to the order of St Mary, whose most famous old boy was Chou En-lai. It is said he showed kindness to Tientsin (as Tianjin then was) when he came to power. On the plane I talk to Lanxin about Mao, Confucianism and western values. He divides his time between Geneva and the School of Advanced Studies. His parents were high-placed CP officials, and he defends Mao. I ask him why there has been no public accounting of the Mao years. He says most Chinese don't write off the Mao era. Mao made lots of mistakes but had good intentions. So did Stalin and Hitler, I reply. But Mao can't be compared to them, says Lanxin, because he didn't deliberately kill people, though millions starved to death as a result of his policies. Anyway, good and bad are combined in every system, every person. Mao had Confucian aspects. His personal life was austere, his descendants are not rich, he wanted an uncorrupt society. Predictably, Lanxin doesn't like the new biography of Mao by Jung Chang and Jon Halliday: "It is the case for the prosecution." Lanxin is a Confucian, and says that only the Jesuits properly understood Confucius. He rejects the idea of the "rise" of China, whether warlike or peaceful. He prefers "restoration."

I have booked in with Lanxin and my "crew" at the Astor House hotel, the oldest European hotel in China, dating from 1863. It is near the "Bund" of old Tientsin, full of palatial banks built in the classical style of the 1920s, with imposing columns and marble interiors. A new extension has been added to the hotel, but I am given a suite in the old part. I lived here with my parents in 1947-48 when my father had got a temporary job as manager and he and my mother were splitting up—something of which I was then unaware. My memory of long, wide corridors has not deceived me—there they are with their darkly panelled walls. I raced my electric car, given to me by my father for my eighth birthday, up and down those corridors.

The manager shows us around the old part of the hotel. Many famous people have stayed and even lived here, and old photographs and portraits of them line the walls—Gustav Detring its founder, General Gordon, Sun Yat-Sen, Herbert Hoover, Ulysses S Grant, the Banchan Lama, Chou En-Lai. Pu Yi, the former boy emperor, and his wife danced the hours away in the Astor's ballroom in the 1920s before he succumbed to Japanese temptation and became the puppet emperor of Manchuria in the 1930s. I persuade the manager to turn on Sun Yat-Sen's metal fan made by Siemens, which performs faintly.

Dinner with Anthony Wong and John Han, fellow old boys of St Louis College. John Han says he was converted to Catholicism, not by the brothers but rather, after he left, by falling for a Catholic girl. When the relationship didn't work out, he lapsed. He then married a Russian and as a result was doubly disgraced. The highest job he could get was deputy librarian in a medical institute. Anthony Wong, a linguist and also a Catholic, was denied a university post until after Mao's death. As a schoolteacher, he was beaten up in the cultural revolution. They are gentle and delightful old gentlemen.

After dinner, I insist on a reconnaissance to Dublin Road, where I lived with my maternal grandmother, my mother's half-sister Tamara and her son Alec. To my horror we find a great hole where No 5 had been—recently created to make way for a subway station. Other houses have survived, but not the drawing room where I played checkers with Aunt Tamara, or the basement where our house boy Shi-tah lived. In his wonderful memoir of Tientsin, The Ford of Heaven, Brian Power says that Dublin Road was full of brothels and bars between the wars. Perhaps these had gone by the time I got there; or perhaps I was simply too young to notice.

Opposite our vanished house, I can see the ghostly outlines of the synagogue, now a ruin. Beyond it the creek, down which bodies occasionally floated, has gone, covered over by a great highway. Underneath it a subway runs where the river used to flow, and beyond it a regiment of skyscrapers, where the streets and shops of the old British concession used to stretch. We went into the synagogue, which had been a restaurant in communist times. Now some people from Israel are trying to raise money to restore it. But how many Jews are there in Tianjin? We meet an old lady of 81, a former communist "veteran." She and her family were allocated accommodation in Dublin Road left by the fleeing Europeans. She remembers "old Soviets" at No 5—it must have been my granny and our family who had stayed on until the early 1950s, when my mother was able to resettle them in Brazil.

24th September, Tianjin A busy day. First, we try to discover my grandparents' shop in Cousins Road. This sold produce from their dairy farm outside Tianjin. The shop was in the old British concession; the street is now a mixture of building site and a maze of dilapidated small houses, shops and restaurants, looking very much as they must have 60 years ago. The bicycles swarm round us. Bent old crones appear from alleyways as news spreads of our arrival and quest. One remembers a Jewish garment factory, long since gone. Another suggests that the dairy shop might have been near the Kiessling restaurant, still in business though not on its original site. The old ladies are courteous, animated, and try to be helpful. Everyone—men and women, young and old—joins in the chatter. One of the great contrasts between China and Russia is the quantity of old people one sees in China. In Russia, the men in particular die off before they are 60. Now China faces a huge ageing problem as the result of the one-child policy. A contrast with India is that there are no beggars. And despite the huge number of people in China, one gets less sense of a sheer weight of numbers than in India.

Another St Louis old boy, Isaac Huang, turns up for lunch with old school photos. All three old pupils are at least five years older than I am, so at school they wouldn't have noticed a midget like me, or I them. The brothers converted Huang to Catholicism, and he had been active in a proscribed Marist organisation, so for 20 years he could work only as a manual labourer.

Then, after lunch, on to the site of St Louis College itself, in the French concession. This massive redbrick Edwardian pile was torn down soon after the communists came and a hospital built in its place. Now the hospital is to be demolished to make way for—a school. I suggest to my team that it be called the New Louis School, as the St would still be considered politically incorrect.

In the school register I am listed as one of 32 entrants on the 23rd September 1947; British by nationality, and Protestant by religion. I was one of only two British, and three Protestant, boys. Most were Catholic and Russian Orthodox, four were classified as "Hebrew" and eight as "pagans." These were Chinese. The brothers took their mission to the heathen seriously, and made strenuous efforts to convert us. I remember Brother Otto trying to convince us that Catholics were superior to Protestants because they gave alms to the poor. I suppose I was sticking up for the Protestants, not just because I was British, but because I was an altar boy at All Saints church. Tientsin, a book by David Hulme, gives a detailed, though by no means flattering, account of me at St Louis. The author relied mainly on the recollections of a Japanese boy called Atsuo Tsukada, who became my best friend, and who remains a good friend. It is painful to read, because I was initially so beastly to Atsuo, teasing him mercilessly for his English (he mixed up his Ls and Rs) and for his "paganism." Peace between us was made by my mother. She invited Atsuo to tea in the Astor House hotel and fussed over him like a long-lost relative. I decided there and then that Atsuo was to be my best friend, though I do not recall that he was consulted in the matter.

On the way to the restaurant for dinner, I took a ride in a bicycle rickshaw of the kind that used to take me to and from school. The 1947 version had brass lamps on either side and a decorated awning. In winter I was covered with a quilt blanket to protect me from truly icy winds from the Mongolian plains. My rickshaw driver had a long nail on his little finger and wore a quilted suit in winter. He would blow his nose and wipe it on his jacket sleeve. The long nail was also used to pick his nose.

It's odd the things children remember. It must have been in the summer of 1948 that we went on a school outing from Tientsin to Peking. The civil war was by this time getting very close and the railway line had been blown up. On our return journey our train had to wait for hours while the track was repaired. But what I chiefly remember from that trip was a huge spitting bowl in the middle of our carriage. I was entranced by the ritual of spitting. At that time the Chinese were great spitters. Today it has mainly gone.

According to the St Louis school register, 27th November 1948 is the last day I attended school. Almost immediately after that we must have been evacuated from Tientsin to Hong Kong on a British destroyer. I remember a HK newspaper headline of December 1948 which went "Fu [the nationalist general Fu Zuoyi] stands firm in North," and another one a little later "Shanghai will be defended to the last drop of blood." Both proclamations were quickly followed by the surrender of the nationalist armies.

25th September, Beijing On the train to Beijing. It's a packed double decker, the journey is only an hour and a half. Check into the Capital hotel near the station: luxurious, with a fine view of the Forbidden City.

I meet the economist David Li of Tsinghua University and director of a think tank sponsored by BP. The Chinese, he told me, save too much because they have such scanty social insurance. Rural people save even more than the urban population, though they have less. He wants the rural population from the middle and western regions to flock to the coastal cities, where, with better social infrastructure, they would save less and consume more. This would do something to correct the Chinese-US payments deficit. But urban congestion would become horrendous, I suggest. I argue for government investment in rural infrastructure instead. He does not believe in this. He is attracted by London as a model of a successful conurbation. Has he ever travelled on the M25?

26th September, Beijing/Harbin A heavy fog hangs over Beijing. Lanxin says it is mainly pollution. We're on our way to the dowager empress's summer palace in the Garden of Clear Ripples, because there are photos of me there in 1948. The palace was looted by the British and French after the opium war of 1856-60, and the empress the built a replacement using naval funds, which is why China was defeated by Japan in 1895. Or so legend has it. It was damaged again after the Boxer rebellion and rebuilt in 1902. It is a wonderful lakeside site full of fine buildings. The most amazing construction is a boat made entirely of marble.

In the afternoon, I give a talk at the China Institute of International Studies, a think tank said to be close to the foreign ministry. Ambassador Ma Zhengang, formerly in London, introduces me with a long explanation of current Chinese foreign policy. Then we hurry off to catch the plane to Harbin.

We arrive at Hotel Modern at 8pm. This is the old hotel which, I'm told, my great-uncle Solomon used for assignations with a lady friend. I am in the suite in which Madame Sun Yat-Sen stayed in 1927 and Chaliapin in 1936. My mother told me about his visit and how they met and how he took her out. She was 18 and very beautiful. The suite is grand, but awkward. To turn off the bath tap one has to walk through the shower. There's an elegant desk but when I plug in my laptop the lights go off.

On my arrival I am met by Qu Wei, the president of the Heilongjiang Provincial Academy of the Social Sciences and director of the Harbin Jews Research Centre, and assorted professors, researchers and translators who keep me talking till almost midnight. They tell me how honoured Harbin was to be visited by an English lord and representative of Harbin's most famous Jewish family. They then hand me a "diary" of banquets, visits and presentations, including a two-hour interview and substantial speech. I see I am to be sucked into their research programme on the Harbin Jews. They are making a film on this theme to promote Chinese-Jewish understanding, world peace and other worthy aims. I am happy to take part in the Jewiash history project, but not to be taken over by it. I say I am deeply interested in the story of the Skidelskys, but my mother's family, which was not Jewish, is of equal interest. Moreover, I was baptised an Anglican, and have been in a synagogue only once in my life, to attend the wedding of my friend Danny Finkelstein. They seem unmoved.

27th September, Harbin In the morning, I am taken by the Jewish committee to the Jewish cemetery on Imperial Hill outside Harbin. Fourteen are in attendance, and there is a tombstone of my great-uncle Moses, who died—presumably in poverty, as his stone is modest—in 1951, aged 76. The original grave, in the city, was dug up and transferred here in 1963. My father used to tell me stories about Moses. He was noted for his good taste and extravagance, and possibly for that reason was eventually excluded from the family business. After the communists came, he was allowed to stay on in Harbin because he had not been active in the Manchurian business, but of course there was no more money coming in. The grave is well kept up by the municipality and by an Israeli charity. A bunch of flowers is thrust into my hands, which I lay on the grave. I am called on to make a speech. What can I say except that I am here to honour my father's family, Harbin and the Jews of Harbin. Graveyards are always melancholy, but even more so when the dead have no connection with the surrounding living.

On the way back from the cemetery, a lady from Xinhua news agency asks me whether Keynes needed to marry. She is clearly quite "advanced." Lanxin says homosexuality was very traditional in China. Confucian mandarins had their boys as well as four or five wives. The current hostility to gays, he says, is a European import. I explain, probably wrongly, that Europeans dislike crossovers—that is, yin-yang. People are expected to be either one or the other, and no one much minds which.

We are going to visit the synagogue. Harbin is now a city of 2.6m inhabitants. [Since my visit, Harbin became notorious around the world in November when benzene leaked into the Songhua river, producing a 50-mile slick.] In the old days of the "eastern Paris," there were about 20,000 Jews embedded in a community of 200,000 Russians and the same number of Chinese. The Jews were caught between the pro-Soviet and antisemitic Russians. But I never heard that my family had been affected by the latter.

I tell the Jewish committee the famous family story of how Solomon won the Mulin coalmine concession from a local warlord, Chang Tso-lin. Both loved poker, but Solomon was the better player. He let the warlord win for six months, and put him in such a good mood that he signed the contract for a 30-year lease without demur. After the visit I am made a research fellow of the Harbin Centre for Jewish Studies, and handed a scroll and mirror.

In the evening, another banquet for 16. The food gets heavier the further north one goes. My stomach protests. At night I have a vivid dream. I am travelling in a coach with a very small, round, amusing Jew. I am much taller than he is. At one point I sit down in what I think is a gap in the seat and send him sprawling off the end on to the floor. He picks himself up reproachfully and squeezes himself back on to the seat beside me. What does this mean? That I am trying to expel the Jew in myself? My dreams have been getting very interesting (to me) and with my BlackBerry it is easy to write them down.

28th September, Harbin Wake up with a headache and the runs. We drive to the Skidelsky house on the Bolshoi Prospekt in Harbin. It is bigger and grander than it appears in the photographs, but a shadow of its former glory. Whereas before it was set in spacious lawns and looked out on to open fields, now the town has crept up on it and it is closed in by skyscrapers. The house was looted in 1945, and like so many similar properties, minimally maintained as an institution—in this case a People's Liberation Army leisure centre. I meet several of these ancients sitting on white sofas around what must have been a sumptuous drawing room. When I am introduced by the director as the "former owner," they greet me warmly. One "veteran" thanks me very politely for letting them use my house! I refrain from saying that it is not with my permission.

The house is on two floors, with a central staircase made of wood curving down to the front hall. I imagine Solomon and his wife (or paramour) descending to greet their guests. The staircase has been painted a hideous brown. The director asks for my advice on the colour for the outside, which is being restored, and when I suggest a light ochre, he says he will pass on my "instructions" to the municipal authority.

29th/30th September, Shanghai Driving back into Shanghai at 8pm. Why are so many of the high-rise apartment blocks dark? Han says most are bought to sell on a rising market so no one ever lives in them. Final meal with Qiujun Zhou, as lovely as ever in a pink dress, and Yang, my faithful cameraman. Next morning the trio—Qiujin, Yang, and Han—come with me to the airport. Fond farewells.

The two films on the flight are Woody Allen's Melinda and Melinda, a tragi-comedy of manners and House of Flying Daggers, a martial arts drama. In the Woody Allen the comedy works, the tragedy doesn't. The Chinese film, set in the 9th-century time of troubles, is fantastical and very moving. Our civilisation can't usually do fairy tales or tragedy, because life is a matter of problems with solutions, whereas fantasy and tragedy require a world without solutions. I wonder how long before the Chinese become like us?