|Hamas has grown to become a powerful force in Palestinian politics [GALLO/GETTY]
Hamas, the Palestinian political movement that controls Gaza, rose to international prominence following its armed campaign against Israel during the second intifada, or uprising, which began in 2000.
The organisation was founded as an offshoot of the pan-Arab Muslim Brotherhood movement during the first intifada in 1987.
By the time the first intifada ended in 1991, Hamas had already achieved widespread popularity in the Palestinian territories for its resistance to the Israeli military occupation and for its social programmes.
The pinnacle of that popularity came in January 2006, when the movement won a stunning victory in the Palestinian parliamentary elections.
But the years since then, marked by a crippling international embargo, internal conflict with rivals Fatah, and Israeli attacks on its members, have proved a testing time for the organisation.
Hamas, which stands for Islamic Resistance Movement, and also means 'zeal' in Arabic, was founded at the beginning of the first intifada by the religious leader Sheikh Ahmed Yassin.
The movement's main goal is to end the Israeli military occupation of the West Bank and Gaza but its charter states its long-term aim is the creation a Palestinian state on what was called Palestine before the creation of Israel in 1948.
It built its popularity on providing support to impoverished Palestinians by constructing schools, hospitals and religious centres.
Unlike many other Palestinian political movements, Hamas has rejected membership of the Palestinian Liberation Organisation, calling for its restructuring, and has opposed signing peace agreements with Israel, although it has offered Israel a number of fixed-term truces.
Israel has assassinated several of the group's prominent leaders, most notably Sheikh Yassin in 2004, and Abdul Aziz al-Rantissi, the movement's leader in its stronghold of Gaza, only a few weeks later.
Sheikh Yassin, already confined to a wheelchair at the time of his death, had been revered by many Palestinians for his calls for armed struggle and uncompromising views regarding Israel.
|Sheikh Ahmed Yassin, who founded Hamas, was assassinated by Israel in 2004 [AP]
Ismail Haniya, the movement's senior figure in Gaza and the deposed prime minister, was a close associate of Sheikh Yassin and once ran his office.
Khalid Meshaal, currently exiled in Syria, has also been a senior political leader of Hamas, since 1995, following the arrest and jailing of Mussa Abu Marzouq, the former Hamas political leader.
Meshaal had led the Kuwait chapter of the organisation, but left the country when Iraq invaded in 1990. He moved to the Jordanian capital, Amman, where he became head of Hamas and survived a failed Israeli assassination attempt.
Hamas leaders have reportedly secured funding through donations from Palestinian supporters both inside and outside the territories, other Arabs and also the Iranian government.
Hamas bolstered its reputation in the 1990s through efforts to maintain order in the often troubled Gaza Strip. Such initiatives earned the group support from unlikely quarters, notably Palestinian Christians and others who have become involved in the organisation.
The movement also became popular for its socio-economic programmes and tough stance on corruption - a problem that some say plagues its Fatah rivals.
|Israel has blamed Hamas for carrying out
rocket attacks from Gaza [AFP]
When peace talks between Israel and the Palestinians broke down once again in 2000, Hamas joined other Palestinian political and armed groups in the second intifada against Israel.
That was marked by a campaign of civil disobedience by Palestinians in the occupied territories, together with an increase in suicide attacks on Israel, often in response to Israeli attacks in the West Bank and Gaza.
The movement's military wing, the Ezzedine al-Qassam Brigades, which is believed to have several thousand members, has also carried out some of the bloodiest attacks in the Israeli-Palestinian conflict.
The Brigades, along with other Palestinian armed groups, have carried out sustained rocket attacks on Israeli towns in the south of the country, often in response to Israeli strikes on Gaza.
On the political front, Hamas has always refrained from participating in an electoral process to join the Palestinian Authority (PA). Hamas viewed the PA as a byproduct of the 1993 Oslo peace process, which the group fundamentally opposed.
But as the second intifada wore on and the PA became weakened under Israeli military occupation, Hamas decided to run as a political party in Palestinian parliamentary elections in 2006.
The group, promising to fight corruption and resist Israeli occupation, overwhelmingly defeated their Fatah rivals, bringing Haniya to power as prime minister.
However, the US, European Union and Israel labelled Hamas a terrorist organisation and, following its 2006 election victory, imposed severe economic sanctions on the Palestinian territories.
Western powers had demanded Hamas recognise the state of Israel, renounce the use of violence and honour previous Palestinian-Israeli peace agreements.
|Hamas took control of Gaza in 2007 after months of Palestinian infighting [AFP]
The PA, which relies on international aid to run the Occupied Palestinian Territories, found itself in a financial crisis percipitated by the economic sanctions.
It was at this time that political tensions between Hamas and Fatah grew.
Rival members clashed in the West Bank and Gaza as the two sides fought bloody battles for control in the territories.
The two parties agreed to form a unity government in early 2007 in an attempt to gain new international aid and overcome their political differences.
That bid failed and the struggle for power culminated in Hamas seizing the Gaza Strip in June 2007. In response, Mahmoud Abbas, the Palestinian president and Fatah leader, cemented his control of the West Bank.
Since then, Israel has moved to further isolate the Hamas-controlled Gaza Strip by tightening the economic sanctions, cutting off electric power to the area, and launching military strikes.
After the end of yet another truce in December 2008, Israel launched a massive military assault on the Gaza Strip, in what it says is an attempt to halt continued rocket attacks emanating from Gaza.
The massive assault would become one of the biggest tests Hamas has faced in its 21-year history.
Hamas survives war
In January 2009, Israel launched Operation Cast Lead and invaded the Gaza Strip after an intense aerial and artillery bombardment campaign.
By the time Israeli troops began withdrawing on January 21, more than 1,300 Palestinians had been killed and thousands wounded. Homemade Qassam rockets and mortars fired from Gaza killed 13 Israelis, ten of whom were soldiers.
|Israel's invasion of Gaza in January left some 4,000 Palestinians homeless
Hamas spokespersons said that the group's leadership and military capabilities had survived the Israeli invasion.
Following a cease-fire with Israel at the end of January, Hamas turned its focus again to its strained talks with Fatah. In February, Ahmed Yousef, an adviser to Haniya, told Al Jazeera that Fatah was an obstacle to Palestinian unity.
He said Hamas has repeatedly failed to convince Abbas to reform and restructure the PLO into a more inclusive entity.
Tensions between the two Palestinian factions worsened when human rights activists in Gaza accused Hamas of "extra-judicial killings" of political opponents, including Fatah members living in the Strip. Hamas leaders promised to investigate the accusations.
In March, international donors pledged $4.5bn in reconstruction aid, but many countries have said they will not deal with the Hamas government in Gaza.
Reconciliation talks falter
Nevertheless, Hamas and Fatah officials continued to hold rounds of talks in Egypt throughout February and March to bridge differences.
Although they agreed to hold elections by January 2010, they continued to differ on key points, namely how to approach existing agreements with Israel.
Other sticking points included the programme of a government and its composition, the leadership of the security apparatus, and the reformation of the Palestinian Liberation Organisation (PLO).
Negotiations reportedly avoided discussing a government of national unity and instead focused on the formation of a government of "consensus".
A fifth round of talks in May also failed to produce results. The international community maintained it would only deal with a Palestinian government that recognises Israel, a concession Hamas is unwilling to make.
Tensions between the two rival factions were further exacerbated when Abbas formed a new government that excluded Hamas members.
Fawzi Barhoum, a spokesman for the movement, said the appointment of the new government would "sabotage" intra-Palestinian talks.
By early June, relations deteriorated into armed clashes and raids against Hamas activists in the West Bank.
In the two years since Hamas took control of the Gaza Strip, the lives of Palestinians there have become inextricably defined by two crises.
An internal political impasse fragmented Palestinian society, reducing the credibility of Palestinian political leaders in the eyes of the public and derailing their people's momentum for national liberation.
|Fatah's Ahmed Qorei, left, speaks with Mussa Abu Marzuq, a Hamas leader, in Cairo [AFP]
Despite the release of Abdul Aziz Dweik, the Hamas speaker of the Palestinian parliament, from an Israeli jail in June, the movement's leaders continued to refuse to recognise Israel as a Jewish state.
"The call by the Israeli leader for a Jewish state is nothing but a racist call, no different from Nazis and other calls denounced by the international community," Meshaal said.
In July, a report released by the British parliament's Foreign Affairs Committee urged the UK government to talk to Hamas, saying that the West's policy of shunning the Palestinian group was showing little sign of success and not helping peace efforts in the region.
Hamas has resorted to a number of different military tactics in its years resisting Israeli occupation. In the past several years, it has moved away from suicide bombings and more toward limited incursion strikes against Israeli military outposts and firing Qassam rockets into Israel.
Recently, however, Human Rights Watch (HRW), a US-based organisation, accused Hamas of endangering civilians when it fired rocket attacks against Israel during the war last January.
Hamas criticised the report, saying it "exempts the occupation from the crimes it committed" and puts " the executioner and the victim on the same footing".
"It is a politicised report lacking objectivity and impartiality," the Hamas information ministry said in a statement.
"Resistance in all its forms is a legitimate right of the Palestinian people as long as they are under occupation and face state terrorism," the statement said.
One of the greatest threats to Hamas' control of the Gaza strip came in mid-August when a little-known pro-al-Qaeda group called Jund Ansar Allah, or Soldiers of the Supporters of God, proclaimed "the creation of an Islamic emirate in the Gaza Strip".
They reportedly claimed Hamas was too liberal and demanded the territory to be governed purely by Sharia, Islamic law.
Within 24 hours, Abdel-Latif Moussa, the group's leader and a number of his followers were killed in clashes with Hamas security forces.
Criticism of Hamas' conduct during and after the war continued in August when the Palestinian Independent Commission, a local human rights group, accused the movement's internal security forces of mistreating prisoners detained in secret locations across the Gaza Strip.
The group said that detainees were beaten, starved and subjected to psychological abuse.
But Hamas officials denied the allegations, and on the eve of the Muslim month of Ramadan, ordered the release of nearly 100 political and criminal prisoners.