Ahmed Qurei, also known as Abu Ala, is the second Prime Minister the Palestinian people have had since April 2003.
Abu Ala is a veteran of the peace negotiations
His predecessor, Mahmoud Abbas, otherwise known as Abu Mazen, resigned in early September after a power struggle with Mr Arafat.
Mr Qurei's elevation to the post was not without its own problems. The former speaker of the Palestinian Legislative Council also clashed with the Palestinian leader over the formation of a new Palestinian cabinet.
Shortly after taking over, Mr Qurei was locked in a lengthy battle with Mr Arafat over who should take over the key interior ministry post.
A leading member of Mr Arafat's mainstream Fatah faction, Mr Qurei was one of the architects of the Oslo peace accords signed with Israel in 1993, which led to Palestinian autonomy in the West Bank and Gaza Strip.
Regarded as a moderate and a pragmatist, he is a banker by trade.
He was born in Abu Dis, Jerusalem, in 1937.
He joined the Fatah wing of the Palestine Liberation Organisation at the end of the 1960s but did not come to prominence within the PLO until the mid-1970s, when he took over its economic and production enterprises in Lebanon.
By 1980, the PLO's business enterprises generated an income of about $40m a year and, with 6,500 full-time employees, ranked as one of the largest employers in Lebanon.
When the PLO was forced out of Lebanon, Abu Ala went to Tunis with Mr Arafat. With the death or assassination of other senior PLO leaders, he gradually gained more influence until he was elected a member of the Fatah central committee in 1989.
That marked the start of his political career, and he began to play an increasing role in peace negotiations.
After playing a key role in the secret Oslo talks he continued to participate in numerous negotiations with the Israelis.
One of his main contributions, according to the Palestinian strategic analyst Yezid Sayegh, was to help put together a Palestinian development plan which was presented to a World Bank conference on aid in 1993.
It was Abu Ala who came up with the idea and found funding for the plan, which then became a central document in the PLO development strategy for the Palestinian territories.
He also helped design the Palestinian Economic Council for Development and Reconstruction (PECDAR) - an organisation channelling international capital - before he was elected to head the Palestinian Legislative Council.
Abu Ala is reported to be a man of great personal charm - tolerant and good-humoured - which has no doubt contributed to his appeal as a negotiator.
His easy-going style has won him friendships over the years with his Israeli counterparts.
Under Palestinian law, if the president dies or becomes incapacitated, it is the speaker of the Legislative Council who becomes head of the Palestinian Authority for an interim period until elections are held.
But Abu Ala may be handicapped by the fact that he has no power base within the PLO.
According to Palestinian political analyst Ghassan al-Khatib, Abu Ala's power is centred on the Oslo structures of the Palestine National Authority, which the Israeli incursions have done much to destroy.