Abbas is also the man being counted on by the United States, the European Union and Israel to revive the peace process and put an end to al-Aqsa Intifada.
A long-term Palestinian Authority stalwart, Abbas became the first Palestinian prime minister in March 2003, emerging from a relatively low-profile role as secretary-general of the Palestinian Authority.
Born in Safed in 1935, Abbas was among the first wave of refugees to leave during the 1948 Arab-Israeli war. He kicked off his academic career with a BA in law in Syria and a PhD in the history of Zionism from the College of Oriental Studies in Moscow.
He moved to Qatar to work as a director of personnel affairs with the Qatari civil service. He organised Palestinian groups in Qatar and came into contact with the then newly-born Fatah movement.
He joined the first central committee, but remained in the background as he was living in Damascus and the Palestine Liberation Organisation was based in Beirut.
He has remained a member of the Palestinian National Council since 1968.
He led the Palestinian delegation to the negotiations with Israeli General Matityahu Peled, which led to the announcement of principles of peace based on a two-state solution (declared on 1 January 1977).
Abbas was a member of the Palestine Liberation Organisation-Economic Committee (PLO-EC) from April 1981 and took over the portfolio of the occupied territories after the assassination of his colleague Khalil al-Wazir (Abu Jihad).
He held secret talks with the Israelis through Dutch intermediaries in 1989 and coordinated the negotiation process at the Madrid Conference in 1991.
Abbas will need to win over those
who doubt his bargaining abilities
Besides being the architect of the secret negotiations that led to the Oslo Accords, Abbas also led the Cairo-based negotiations, which have become known as the Gaza-Jericho Accord.
Abbas has been chairing the PLO's negotiation affairs department since its foundation in 1994, and spearheaded the PLO's international relations.
He returned to Palestine in July 1995 and was appointed secretary-general of the PLO's executive committee in 1996.
Abbas was touted by politicians in Washington and London as the Palestinian moderate who would rescue the peace process.
Being championed by the US and Britain, however, might have been a double-edged sword, especially given his lack of strong support among Palestinians. He resigned just seven months later.
In some Palestinian circles, Abbas, also known by his nom de guerre Abu Mazin, is often discounted as an Israeli appeaser.
Despite his repeated calls for a halt to military operations by the Palestinians against the occupation, Abbas is said to qualify his condemnations as a tactical rather than a moral stand.