Hamas is a militant and political Islamist group operating in the West Bank and Gaza. Hamas is designated as a terrorist organization by much of the international community, but enjoys wide support from Palestinians as a legitimate force against Israel’s occupation.

The movement was founded as an offshoot of Egypt’s Islamic Brotherhood, and in 1987 Hamas spiritual leader and founder Sheikh Ahmed Yassin established the movement’s military wing, which became known as Hamas. In 1988, in the wake of the outbreak of the First Intifada, Hamas published its official charter, in which it announced its departure from nonviolence in its struggle against Israel.

Hamas’ popularity among Palestinians comes partly from its tradition of providing welfare programs, such as schools and hospitals. The militant wing of Hamas adheres to the movement’s 1988 charter which calls for the liberation of all of historic Palestine, and views all lands under Israel’s domain as part of an Islamic Waqf, of which every inch must be liberated.

The signature of the 1993 Oslo Accords between Israel and the Palestine Liberation Organization (PLO) was viewed by the Hamas leadership inside the territories and in exile as a violation of Palestinian rights, and in 1993 Hamas launched its first suicide attack inside Israel, a practice that it would uphold from then on, causing massive Israeli civilian casualties.

Hamas leaders have long been the target of Israeli assassinations. Yassin was killed in 2004 in a missile strike as he left a mosque in Gaza. His Hamas co-founder, Abdel Rantisi, was killed weeks later in an Israeli air strike. In 1997, Hamas political leader Khaled Meshal was the target of a botched assassination attempt by agents from Israel’s Mossad espionage agency operating covertly in Jordan. Meshal’s life was saved when Israel agreed to hand over the antidote to the toxin used on him, in return for the release of the two Mossad agents caught and held in Jordan during the assassination attempt. Yassin, who was in an Israeli jail at the time, was released under the terms of the agreement.

Long-standing tensions between Hamas and the secular Fatah came to a head following the 2006 Palestinian legislative elections, which gave Hamas a decisive victory and put it in charge of the political regime in the Palestinian territories. Hamas’ Gaza chief, Ismail Haniyeh, was named Palestinian prime minister, but Hamas’ status as a terror group resulted in immediate sanctions from Israel and other Western countries. The group rejected demands to adhere to previously signed peace agreements, renounce violence and accept Israel’s right to exist, and the sanctions were upheld.

Meanwhile, tensions with Fatah grew as the two factions attempted to cooperate with the framework of a unity government, but when the attempt failed and Palestinian Authority President Mahmoud Abbas dissolved the government, bloody clashes erupted between Hamas and Fatah in Gaza, resulting in the seizure of the area by Hamas in June 2007.

There have been numerous attempts by neighboring Arab countries to end the Hamas-Fatah rift, and form a unified Palestinian leadership. The failure of the two groups to come together has perpetuated the continuing division within the Palestinian Authority, with Fatah as de facto rulers in the West Bank, and Hamas firmly in control in Gaza.