This paper analyses the popular support to Hamas, the most important of the Palestinian Islamist movements today. The paper charts the movement's historical ascendancy from a fringe Gaza-based group to a mainstream Islamist movement and mouthpiece for dispossessed Palestinians. Since 2001, Hamas's leadership has come under increasing attack from Israel, killing a number of the movement's leaders and senior members, most prominently Sheikh Yasin, the movement's founder and spiritual leader, and his successor as Hamas leader, Abd al-Aziz Rantissi. Nonetheless, Hamas's duality as "worshippers" and "warmongers" has made the organisation extraordinarily popular among dispossessed Palestinians and a mounting political challenge to the secular nationalism of the PLO. At present, two-thirds of the Palestinians live below the "poverty line" and it is likely that it is in this disenfranchised segment of the population that Hamas finds its core support. Presently, about one in every six Palestinians in the Occupied Territories benefits from support from Islamic charities. Hamas, on its part, allocates almost all of its revenues to its social services, but there is no evidence that Hamas or the other Islamic charities provide assistance conditional upon political support.