Ahmad Jabari was a high-ranking member of Hamas and in command of the movement's military wing, the Ezzedine al-Qassam Brigades, in the Gaza Strip.
He was killed in an Israeli air strike on his car in Gaza on November 14.
Jabari began as a member of Palestinian President Mahmoud Abbas's Fatah party, but switched his allegiance to Hamas after serving 13 years in an Israeli prison, where he met several Hamas leaders.
Jabari survived four previous attempts by Israel to kill him. In one attempt in 2004 his eldest son, his brother and three other relatives were killed. He also survived several attacks on the Ezzedine al-Qassam Brigades.
Nicknamed Abu Mohammed, Jabari was born in 1960 in the eastern Gaza neighbourhood of Shejaiya.
In 2006, he became the acting commander of the military wing of Hamas after his predecessor Mohammed Deif was severely wounded in an Israeli attack. The previous head of the Brigades, Salah Shehadeh, was killed by Israel in 2002.
After Jabari's killing, the Israeli army said in a statement that he was "directly responsible for executing terror attacks against the State of Israel in the past number of years".
Jabari was credited with leading the bloody 2007 takeover of Gaza from Fatah forces, developing Hamas's military arsenal and its networks in Iran, Sudan and Lebanon.
He also played a key role in the capture and release of Israeli soldier Gilad Shalit, who was kept as a prisoner for more than five years.
Shalit was ultimately exchanged for 1,027 Palestinian prisoners in 2011.
Hamas has ruled Gaza since 2007, and repeated attempts to reconcile with Fatah have failed.