Was this man a charismatic religious leader, or the uncompromising fomenter of violence?

It was last September, the day after what now looks like a trial run for the killing of Sheikh Ahmed Yassin, easily the highest profile victimof Israel's policy of targeted assassinations.

It was last September, the day after what now looks like a trial run for the killing of Sheikh Ahmed Yassin, easily the highest profile victimof Israel's policy of targeted assassinations.

Then, he had escaped virtually uninjured when a 250lb laser bomb dropped from an Israeli airforce F-16 half-destroyed a house where the Hamas leader had been eating lunch with friends and associates. When we came upon him in the modest house - less than 100 metres from where he was later killed by an Apache helicopter missile - he was stretched out on a bed smiling benignly at the stream of visitors, covered in a spotless white sheet which matched the colour of his ample beard. He had little to say, beyond the predictable, commenting only that "God has saved us" and adding, by way of justifying his warning the previous night that "the Israeli people will pay a price for this crime", that "all Palestinian people have a right to defend themselves".

But you could see in the obsequiously respectful faces of his visitors - including two uniformed Palestinian Authority security officers - the dual role he had occupied for so long. The founder of Hamas, the architect above all other factions of the suicide bomb aimed at slaughtering civilians, was for Israelis the fomenter par excellence of militant violence. For many Palestinians, not only limited to the ranks of Hamas itself, he was a charismatic - if utterly uncompromising - "spiritual leader" and spokesman. Sheikh Yassin was born in Joret Askalan, a village near Ashkelon, in what has been Israeli territory since 1948, before his family fled as refugees to Gaza. Like Yasser Arafat he lost a parent in early childhood, his father dying when he was five. His family of seven was poor, and he used to visit Egyptian military camps to collect left- over food to feed his family.

He injured his spinal cord while either exercising or playing football on the beach in Gaza in 1952, at the age of 16. He was paralysed from the neck down, blind in one eye and grew increasingly deaf. From his relatively early years, contemptuous of the failure of other Arab regimes to help the Palestinians, he believed that only the Palestinians could help themselves. The Hamas website quotes Sheikh Yassin as declaring: "The Arab regimes had disarmed us, under the pretext that there is only one Arab force. Our destiny has been linked to it. We had been defeated with the defeat of the Arab regimes. The Zionist gangs slaughtered us. If we had been holding our weapons, things would have been changed."

It was at al-Azhar University in Cairo where he joined the hardline Muslim Brotherhood. As a teacher of religion and Arabic for some 20 years, he also regularly preached in the mosques of Gaza that a strict adherence to Islam was an essential prerequisite to the reclaiming by Palestinians of their land lost to Israel.

In 1984, he was arrested for organising an armed group linked to the Muslim Brotherhood and for possessing weapons. For the first of two occasions he was released a year later as part of a prisoner swap, this time in return for Israelis captured by the small militant Palestinian faction led by Ahmed Jebril. Hamas was founded in 1987 at the start of the first Palestinian intifada, or uprising, against Israeli rule, at a time when there were complaints that the Muslim Brotherhood was not doing enough in the struggle against Israel.

He declared as recently as January: "We will not bow to pressure, and resistance will continue until the occupation is destroyed."

Consistently described as Hamas's spiritual leader, he was directly engaged in forming its military wing (Qassam) and its security wing (Majd). Sheikh Yassin was imprisoned by Israel in 1989, sentenced to life plus 15 years, and subsequently convicted by a military court on charges which included incitement to kidnap, killing soldiers and founding Hamas and its military and security wings.

On 1 October 1997 he was released during the premiership of Binyamin Netanyahu in exchange for two Mossad assailants who had tried to kill Khaled Mishaal, a leader of Hamas in Jordan. Married - his widow's name is Halima - he had eight daughters and three sons. Once released he returned to Gaza, where he injected new life into Hamas, which is officially committed to the destruction of Israel. He was placed under house arrest by the Palestinian Authority several times.

All that said, it was not hard, on the streets of Gaza City yesterday, to see the reverence in which Sheikh Yassin was held by many supporters as well as active members of Hamas. There is no doubt that for some Gazans, Sheikh Yassin represented a more attractive, more extreme and less corrupt figure than Yasser Arafat. At the cemetery where he was buried yesterday a woman who named herself only as Om Bilal, wearing the traditional hijab with only her angry eyes visible through her headcovering, declared: "He was the leader of the nation who had done many good things. His being a martyr makes us proud. Everyone holds their chin up high and this will make everyone become Hamas members."

This goes to the heart of the question of whether by extinguishing Sheikh Yassin, Israel can really, as Sylvan Shalom, its Foreign Minister, suggested yesterday in Washington, bring Hamas to the view that its militant policies do not pay. Or rather whether he will join the ranks of martyrs as an example to more Palestinians to take up the armed struggle against Israel. One possibility is that Abdel-Aziz Rantissi, who uttered dire warnings of vengeance here yesterday, will take on the leadership role in Hamas vacated by Sheikh Yassin. The older generation has gone, including people like Abu Shanab, who had suggested that Hamas might accept the two-state solution, at least as an interim measure, but who was assassinated last year. There is now a possibility that a new generation of Hamas leaders could start to come forward. What is more bleakly probable is that the vengeance promised in his name will be wrought - if the past is anything to go by - with speed and ferocity.