Thousands of cheering supporters turned out to watch him vow revenge for an attempt on his life in September 2003 by Israeli forces which left him injured.

Born in 1938 in what was then Palestine under the British mandate, Sheikh Yassin's political views were forged at a time of humiliation and defeat for Palestinians.

After a childhood accident left him a quadriplegic, he devoted his early life to Islamic scholarship and studied at al-Azhar university in Cairo, the birthplace of the Muslim Brotherhood.

It was there that he formed the belief that Palestine was an Islamic land "consecrated for future Muslim generations until Judgement Day", and that no Arab leader had the right to give up any part of this territory.

Sheikh Yassin became actively involved with a Palestinian branch of the Muslim Brotherhood but he did not come to widespread prominence until the first Palestinian intifada of 1987.

It was then that the Palestinian Islamist movement adopted the name Hamas, meaning "zeal" and also an Arabic acronym for "Islamic Resistance Movement", and he became its spiritual leader.

In 1989, Sheikh Yassin was arrested by the Israelis and sentenced to life imprisonment for ordering the killing of Palestinians who had allegedly collaborated with the Israeli army.

He was eventually released in 1997, in a trade-off with Jordan for two Israeli agents involved in an assassination attempt on a Hamas leader in Jordan.

During his time in prison, his importance as a symbol of Palestinian resistance had grown - but his popularity still fell far short of that enjoyed by Yasser Arafat.

Believing that a divided leadership would undermine Palestinian interests, Sheikh Yassin sought to maintain good relations with the Palestinian Authority and with other regimes in the Arab world.

But he remained uncompromising on the issue of peace. "The so-called peace path is not peace and it is not a substitute for jihad and resistance," Sheikh Yassin repeatedly said.

He attacked the outcome of the 2003 Aqaba summit in Jordan, attended by the Israeli and US leaders as well as the then Prime Minister Mahmoud Abbas, who pledged an end to violence.

Militant groups like Hamas did initially declare a temporary truce, but that unravelled in July 2003 after Israeli forces killed two Hamas members in retaliation for the suicide bombing of a Jerusalem bus that left 21 people dead.

Hamas has been able to build support by offering material help to Palestinians suffering economic hardship during the latest intifada.

It has established charitable funds to establish schools, clinics and hospitals that provide free services to families in distress and has been able to attract millions of dollars from the Gulf and elsewhere.

Sheikh Yassin himself proved a powerful inspiration for young Palestinians disillusioned with the collapse of peace hopes.

He inspired them to offer up their lives, promising that suicide bombers who were willing to die for the sake of the dignity of Palestinians and in the service of a longer-term victory would achieve martyrdom.

Attempts to restrict Sheikh Yassin's activities met with fierce resistance from his supporters.

In December 2001, one man died in clashes with Palestinian police after Sheikh Yassin was placed under house arrest.

Shooting erupted again in June 2002 when Palestinian police surrounded his house, following a spate of bloody suicide bombings against Israel.

And, in September 2003, the Israeli army attempted to kill Sheikh Yassin, while he was at the house of a Hamas colleague in Gaza.