Mahmoud Abbas, also known as Abu Mazen, was named as chairman of the Palestine Liberation Organisation (PLO) after Yasser Arafat died in November 2004, and in January 2005 he won convincingly in the election for president of the Palestinian Authority.
Mahmoud Abbas co-founded Fatah with Yasser Arafat
Mr Abbas was the nominated candidate of the main Palestinian political faction Fatah, and the clear front runner throughout the campaign.
He was also the man favoured by the international community and Israel to succeed Arafat.
He was the authority's prime minister from May 2003 until his resignation almost four months later.
His leadership then was meant to open a new, post-Yasser Arafat, chapter in Israeli-Palestinian relations in which the peace plan known as the roadmap was meant to lead both sides towards resolution.
But, on one side the bitter struggle between the Israel and Hamas has left him on the sidelines. On the other, the power struggle with Arafat - who had refused to hand over crucial powers to Mr Abbas - limited his ability to act and took up much of his time.
Born in Safed in British Mandate Palestine in 1935, he is one of the few surviving founder members of Fatah - the main political grouping within the PLO.
In exile in Qatar during the late 1950s, he helped recruit a group of Palestinians to the cause. They went on to become key figures in the PLO.
He co-founded Fatah with Arafat and accompanied him into exile in Jordan, Lebanon and Tunisia. In the early days of the movement, he became respected for his clean and simple living.
A highly intellectual man, 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.
They claim he downplayed the number of victims and accused Jews of collaborating with the Nazis.
He denied that charge in an interview with the Israeli daily Haaretz in May 2003.
"I quoted an argument between historians in which various numbers of casualties were mentioned. One wrote there were 12 million victims and another wrote there were 800,000," he told the newspaper.
"I have no desire to argue with the figures. The Holocaust was a terrible, unforgivable crime against the Jewish nation, a crime against humanity that cannot be accepted by humankind," he said.
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.
This enabled him to become a successful fundraiser for the PLO and to take on an important security role in the early 1970s, before being appointed head of the PLO's department for national and international relations in 1980.
Mahmoud Abbas, regarded as a pragmatist, was one of the main initiators of the dialogue with Jewish left-wing and pacifist movements in the 1970s and in the difficult years before negotiations were eventually started between Israel and the Palestinians.
Yasser Arafat came under intense international pressure to choose a premier
Widely regarded as the architect of the Oslo peace process, he accompanied Arafat to the White House in 1993 to sign the Oslo Accords.
Referring to the current intifada, Mr Abbas has called for a halt to armed attacks on Israeli targets to avoid giving Israel a pretext to destroy the last vestiges of Palestinian autonomy.
In the light of his origins in Safed in Galilee - in what is now northern Israel - he is said to hold strong views about the right of return of Palestinian refugees. In the newly-formed Palestinian Authority, Mr Abbas took over the refugee file and pushed for progress on this issue.
It is his view that: "Everyone should first be granted the right of return, but then we have to sit down and discuss the details that have to be jointly agreed upon and mutually acceptable to both sides."
After a protracted dispute with Arafat, Mr Abbas was named interior minister as well as prime minister of the new Palestinian cabinet.
He stood down in September 2003, after a power struggle with Arafat over control of Palestinian security forces.