Ahmed Jabari was the commander of Hamas’ military wing – the Ezzedine al-Qassam Brigades. He was born in Gaza city in 1960, and was a former member of Fatah. He left Fatah and joined Hamas, later becoming its military leader. He is a father of 14, and was responsible for the kidnap of Israeli soldier Gilad Shalit, the negotiations regarding Shalit, and his eventual release.
Obituary:
http://www.aljazeera.com/news/middleeast/2012/11/20121114154425326133.html