The Popular Front for the Liberation of Palestine (PFLP) was formed as a resistance movement by the late George Habash after the occupation of the West Bank by Israel in 1967.
Combining Arab nationalism with Marxist-Leninist ideology, the PFLP saw the destruction of Israel as integral to its struggle to remove Western capitalism from the Middle East.
During the 1970s the group fostered links with militant groups across the world, including the German Baader Meinhof organisation and Japan's Red Army.
Working with other groups, the PFLP pioneered aircraft hijackings as a high-profile means of drawing attention to their movement, most notably with the capture of an Air France plane in 1976.
The plane was flown to Entebbe in Uganda where, after a stand-off, Israel launched a dramatic commando raid to rescue nearly 100 hostages.
During the 1970s, the PFLP was the second largest faction in the Palestine Liberation Organisation (PLO), but pursued a markedly different strategy to Yasser Arafat's dominant Fatah organisation.
While Fatah attempted to build support for the Palestinian cause from Arab countries, the PFLP became disillusioned with what it saw as inertia among Middle Eastern leaders. Instead, the PFLP enlisted backing from the USSR and China.
But the decline and collapse of the Soviet Union during the late 1980s undermined the PFLP, and the group lost ground to Islamist movements, particularly Hamas.
Attempting to bolster its position after the 1993 Oslo peace accord, the PFLP added its weight to a disparate group of Palestinian organisations opposed to the deal.
It boycotted Palestinian elections in 1996, but three years later the PFLP accepted the formation of the Palestine Authority and sought to join Yasser Arafat's administration.
The group's deputy secretary general and former military wing commander, Abu Ali Mustafa, was allowed by the Israel authorities to return to the West Bank from Syria.
Considered a moderate within the group, Mustafa succeeded the ailing Habash in 2000. However, he was killed the following year when an Israeli military helicopter fired rockets at the PFLP's office in Ramallah - a sign, said some analysts, of how Israel saw the PFLP as a continuing force.
Indeed, the group struck back by shooting dead Israeli Tourism Minister Rehavam Zeevi, leader of a right-wing party, in Jerusalem.
Mustafa's hardline successor, Ahmed Saadat, was accused by Israel of ordering the killing. In 2002 the Palestinian Authority imprisoned him in Jericho after he and four others were convicted by a makeshift court with police officers acting as judges and lawyers.
Saadat was one of three PFLP candidates to win election to the Palestinian parliament in January 2006, but two months later Israeli troops besieged the Jericho prison and seized him and the four others so they could be put on trial in Israel.
The PFLP leader was subsequently sentenced to 30 years in an Israeli prison for heading an "illegal terrorist organisation" but was never charged with Zeevi's murder due to a lack of evidence.
Saadat's incarceration did not stop the PFLP's military wing, renamed the Abu Ali Mustafa Brigades, launching attacks on Israeli targets.
During the second Palestinian intifada, or uprising, it carried out five suicide bombings between 2002 and 2004.
In recent years, the group has been involved primarily in firing rockets and mortars from the Gaza Strip at communities in southern Israel. It has also claimed responsibility for numerous attacks targeting Israeli forces patrolling the Gaza frontier.
In 2011, two men affiliated to the PFLP were convicted of killing five members of the Fogel family at the Jewish settlement of Itamar, near the West Bank town of Nablus. Despite their links to the group, Israeli prosecutors said they had carried out the attack on their own initiative.
It was also not clear how involved the PFLP leadership had been in the attack in November 2014 that saw two members of the group armed with axes storm a synagogue complex in West Jerusalem and kill four rabbis in the middle of their morning prayers.
A statement by the Abu Ali Mustafa Brigades praised the "heroic operation" by Ghassan and Uday Abu Jamal, but did not specify whether the cousins had been instructed to carry out the attack.
Although the PFLP has in the past called for the "liberation" of all of historic Palestine, the group's national congress declared in 2000 that it accepted the "new realities" created by the Oslo accords could not be ignored.
It instead sought the establishment of a Palestinian state with Jerusalem as its capital, the withdrawal of Israeli soldiers to the 1967 borders, the dismantling of Jewish settlements on occupied territory, and the right of return for Palestinian refugees.
However, in 2010 Saadat warned against peace talks with Israel and said the Middle East conflict could only be resolved through the creation of a state shared by Palestinians and Jews.
He said negotiations were "nothing but a cover for the continuation of an Israeli policy built on the continuation of occupation".