Mahmoud Abbas, the PLO secretary general, also known as Abu Mazen, was, until recently, the most senior Palestinian after Yasser Arafat.

He was the prime minister from May 2003 until his resignation almost four months later.

Born in Safed in British Mandate Palestine in 1935, he co-founded Fatah with Yasser Arafat and accompanied him into exile in Jordan, Lebanon and Tunisia.

Mahmoud Abbas studied law in Egypt before doing a doctorate in Moscow. He is the author of several books.

But some Jewish groups have criticised both his doctorate and the resulting book, The Other Side: the Secret Relationship Between Nazism and Zionism, as works of Holocaust denial.

Mahmoud Abbas always kept to the background, but also built up a network of powerful contacts that included Arab leaders and heads of intelligence services, which helped him to raise funds for the PLO.

Regarded as the architect of the Oslo peace process, he accompanied Arafat to the White House in 1993 to sign the Oslo Accords.

Photograph: PPO via Getty Images and AFP/Getty Images