Meet the community's £50 million benefactor

Marks was born in London, the son of a businessman in the clothing trade. "My father taught me business ethics," he says, something he remembered when he founded the Jewish Association for Business Ethics. His grandfather, Samuel Bernei, who was an executive of Columbia Pictures in Britain - "he brought Rudolph Valentino to this country" - had had the same belief.

When I was at Wellington school, I punched a much bigger boy who called me a dirty jew

Marks's work for the London School of Jewish Studies - he still likes to call it Jews College - represents his favourite "baby". And that is probably only right for the man who is its president. He wants the community establishment to take the school - whose mission is to teach adults Jewish knowledge - more seriously. "The United Synagogue tried to sabotage it," he maintains. "That almost broke my heart."

He himself does not claim to be more than "traditional" but then adds: "I won't mind being called 'frum'. I go to shul on Shabbes and I like to read the Torah and the Rashi commentaries. I've always been the same - it is not a sudden conversion. I don't belong on the left and I don't belong on the right."

Even so, his fund has helped the Reform movement in Britain, although he is a devoted member of Hampstead Synagogue. He loves the sound of a good chazan but is critical of many of Britain's rabbis, whom he says "do not convey enough about the nature of belief" from the pulpit.

Marks's own education was at Wellington, a public school that, during the war, was based in Somerset. It was there that he experienced his first examples of antisemitism. "I punched a much bigger boy who called me a dirty Jew". As a result, he trained to be a boxer, which he took up seriously at his next school, Charterhouse.

His schooling instilled an idea of Britishness that is as much a part of his make-up as his Jewish heritage. It was enhanced when he spent his national service in the RAF. He decided to try for air crew, which was aiming a little high, both philosophically and practically. He was told that he had to be tall (he is 5ft 3 inches) and had to have perfect eyesight (he wore glasses).

But while his request was being considered and summarily turned down, he managed to sneak a glance at the note which the interviewing officer had made. "It said: 'Aircraftsman Marks is a Jew and knows all the answers'. It gave me a certain courage to go forward in my life," he says.

From the Air Force, he became a chartered accountant. His most notable client was the property magnate, Arnold Silverstone, who was to become Lord Ashdown. He worked with him on his most important project - redeveloping the south end of London's Victoria Street. Before he died, Lord Ashdown directed Marks to establish a trust that would promote good causes, mostly for Anglo-Jewish projects.

Ashdown, he remembers fondly, told him: "We are Jews. We have to bring our code of honesty and integrity into business."

The trust really got going in 1977 and the number of causes it helped multiplied incredibly. It supported ORT in its various projects, notably travelling on its behalf to Argentina, Peru and Uruguay, not just to set up Jewish schools, which was its principal aim, but also to provide food and shelter for poor Indian families.

The trust took under its wing the Yakar Education Centre in Hendon and Tel Aviv. Today, it also supports the London Jewish Cultural Centre, an institution Marks thinks is "wonderful".

He is nothing if not thoroughly international in his approach. When he heard, through Chabad, of the devastating effect on Jewish children of the Chernobyl nuclear leak, he immediately set to work. As a result, hundreds of children from the area were treated, and many of them brought to Israel.

He established the UJIA-Ashdown Fellowship, which helps students to spend their gap years studying in Israel and the United States. But Russia remains high on his list, which is why he has funded a Jewish school in Sverdlosk.

He and his wife Adrienne, who has always advised him on which ideas would work and which would not, travelled to Laos and Cambodia. The trust provided seed money for prostheses and false limbs to be issued to people mutilated by anti-personnel mines still lying in the killing fields.

"We had heard that, among the mad things Pol Pot did, was cut off communication with the outside world. With our help, they now have internet connections and satellite phones, which means people there can phone anywhere in the world," he says.

None of this should give the impression that Marks is simply a do-gooder. Or taking sole credit for the trust's work. He acknowledges the fact that his fellow trustees, his brother-in-law Richard Stone and their cousin Jonathan Silver, have played an immense part. But Marks is the man who really made it all work.

He is also undoubtedly a man of passions, none more so than his love of music, exemplified by his efforts to get the Royal Philharmonic Orchestra on to a financially stable footing. Through him, the trust has poured hundreds of thousands of pounds into the London College of Music and, more recently, its parent body, the new University of West London. "This is not a Clive Marks ego trip," he emphasises. "Music is one of the most important parts of my life."

He has organised and, of course, financed, via ORT, a website that is an extensive study of music during the Holocaust. It is said to be the most valuable of its kind, with 300 articles and a bibliography of 200 entries. The website lists events, people and the camps where they wrote and played their last notes. Marks says: "People have scant knowledge of the Holocaust. Many, however, do have an interest in music. We aim to reach them through this interest."

So, after almost 35 years at the helm, Marks can look back at the trust's work with some satisfaction.

"I should be very pleased to think that we have enabled things to be done that wouldn't have happened otherwise. And, just as important, to be able to act quickly."