|Rayyan came to be considered as Hamas's highest religious authority [AFP]
Nizar Abdul Kader Mohammed Rayyan was born on March 6, 1959, in the Jabaliya refugee camp in the Gaza Strip.
He attended universities in Saudi Arabia, Jordan, and Sudan, where he received a PhD in Islamic studies.
Back in Gaza, Rayyan served as a preacher at several mosques and as a professor of Islamic law at the Islamic University.
Married to four women, Rayyan was a father of six sons, six daughters and a grandfather of two.
Fundamentally opposed to the state of Israel, Rayyan once proclaimed: "We will never recognise Israel. There is nothing called Israel, neither in reality nor in the imagination."
Rayyan was arrested several times by Israel and the Palestinian Authority (PA) before Hamas took control of the strip in June 2007.
He was among a group of Hamas leaders who founded the Islamic Salvation Party when the Palestinian Authority was formed in 1994.
He was also engaged in Hamas's negotiations with the Palestinian factions and served as one of the main political leaders of the movement.
An influential preacher at what is known in Jabaliya as the "Mosque of martyrs", Rayyan supported suicide bombers. He even sent his own son on a suicide mission, which left two Israelis killed at Rlei Sinai.
After Hamas ceased suicide bombings against Israel, he advocated for their renewal.
In 2004, Rayyan became Hamas's highest religious leader after the Israeli forces killed Sheikh Ahmed Yassin.
Rayyan was the mastermind of the Ashdod Port attack in Israel, which killed 10 people in 2004.
He was one of the architects of the factional fighting between Fatah and Hamas in Gaza in 2007 that resulted in Hamas taking control of the Gaza Strip.
Rayyan, his four wives and 11 of his children were killed in an Israeli strike on his residence on January1, 2009.