Harakat al-Muqawamah al-Islamiyya (Islamic Resistance Movement). The word "Hamas" stems from a term that means courage and bravery.

Hamas mainly operates in the West Bank and Gaza Strip. The group's headquarters have been located in Syria. Media reports have alleged that some Hamas leaders shifted to Sudan.

The avowed primary goal of the Islamic Resistance Movement is the establishment of an Islamic state throughout Palestine. The group ultimately seeks to escalate its armed resistance, and total jihad (holy war), with the participation of all Muslims.

The number of hardcore members is unknown; however, the group has the backing of tens of thousands of supporters and sympathizers.

Hamas' strong financial backing is one of the primary reasons for its efficacy. The organization has used a network of foreign governments, charity organizations, business fronts and individual donors to build up a war chest estimated in the tens of millions of dollars every year.
 
In an effort to plug the monetary flow to the terrorist group, several countries, including the U.S, U.K. and Germany, cracked down on these sources.
 
Hamas receives money from unofficial bodies in Saudi Arabia, the Gulf states and Iran, with Iranians reportedly contributing around $3 million a year.
 
Four central Hamas charities operate in the West: the Palestinian Relief and Development Fund (U.K.); the Holy Land Foundation (U.S., assets currently frozen); Al Aqsa Foundation (Germany, with branches in Holland and Belgium); and the Comite de Bienfaisance et Solidarite avec la Palestine (France).
 
A limited number of economic projects (sewing and weaving centers, cattle farms and symbolic payment for other services) produce a small portion of the group's income. Other fund-raising methods add to the total.

Until January 2006, the Harakat al-Muqawamah al-Islamiyya conducted numerous attacks, including suicide bombings, assassinations, mortar attacks and armed strikes against Israelis. Hamas also attacked Palestinian rivals, including members of Yasser Arafat's Fatah faction.
 
The Izz el-Din al-Qassam Brigades, the armed wing of Hamas, has been held responsible for most of the group's violent operations. Hamas has also engaged in non-violent activities, including the operation of social programs such as schools and hospitals.
 
Since Hamas won the Palestinian legislative elections in January 2006, the group has been deeply involved in Palestinian politics and has struggled with its position regarding violence. On Feb. 8, 2006, Hamas head Khaled Mashal, speaking in Cairo, stated that "anyone who thinks Hamas will change is wrong," insisting that while Hamas was willing to have a cease-fire with Israel, its long-term goal remained the elimination of Israel through jihad.
 
On Feb. 13, 2006, in an interview with the Russian newspaper Nezavisimaya Gazeta, Mashal declared that Hamas would cease violence against Israel if it recognized the 1967 borders, withdrew from all Palestinian territories (including the West Bank and East Jerusalem) and recognized Palestinian rights, including the "right of return." This was the first time a top Hamas official spoke publicly about an eventual end to its armed struggle.
 
In May 2006, Hamas leaders threatened a new intifada and said they would decapitate anyone who tried to bring down its Cabinet. In November of that year, Hamas called on Muslims to attack American targets due to U.S. support for Israel.
 
Hamas also continued to engage in violence against Palestinian members of the rival Fatah party, which it considers to be not militant enough in its stance against Israel.

Since 2007, Hamas has essentially run Gaza, while Fatah directs the Palestinian Authority governing the West Bank.

Hamas rockets into Israel helped spark an Israeli assault in late 2008 and early 2009.

Following the 1992 Gulf War, Hamas became the leading terrorist group operating in the West Bank and Gaza Strip. Because of Hamas' strength, the Fatah organization that was long led by Yasser Arafat viewed Hamas as a threat to unity among secular nationalists.
 
The group's organizational and ideological structures stem from the Muslim Brotherhood (MB) movement that was started in the 1920s in Egypt. Hamas was formed in late 1987, eventually expanding its operations into the first intifada (uprising) of the late 1980s and early 1990s.
 
The group gained momentum as the intifada grew, eventually becoming the dominant Islamic fundamentalist organization in the region. Hamas continues to be the most powerful opposition to the peace process. It has also recruited and trained suicide bombers against civilian and military targets in Israel.
 
Hamas is loosely structured, with some cells working secretly and others overtly. It also operates a number of public social services for Palestinians. Hamas works openly through mosques and social programs to raise funds, recruit members and distribute propaganda.
 
Sheikh Ahmed Yassin, a wheelchair-bound Islamic cleric, was the founder and spiritual head of Hamas until he was assassinated in a missile attack by Israel in March 2004. Yassin became involved with the Muslim Brotherhood, and gained notoriety during the first intifada in 1987. He was arrested by Israeli authorities in 1989 and released in 1997.
 
Between September of 2000 and March of 2004, Hamas perpetrated 425 terrorist attacks, resulting in the deaths of 377 Israelis and the wounding of more than 2,000 civilians and soldiers, as reported by the Jerusalem Post.
 
Following Yassin's assassination, Abdul Aziz Rantisi was selected to be the new leader of Hamas in Gaza. Rantisi, a pediatrician, previously acted as a Hamas spokesman. After gaining his leadership position, Rantisi vowed the organization would reject all compromise with Israel and pledged to kill Prime Minister Ariel Sharon.
 
Less than a month after being named leader, Rantisi was also assassinated in a missile strike on his car by Israeli gunships. Hamas did not disclose the name of its new leader for fear of another assassination. However, Israel subsequently identified Mahmoud A-Zahar, a deputy to Rantisi and Yassin's personal physician, as the new leader of Hamas.
 
Israel and Hamas made mutual threats to increase strikes outside of Israel after a Hamas suicide bombing in Be'er Sheva on Aug. 31, 2004. Israel promised that terrorists who were located in other countries would not be immune from attacks on Hamas leadership, specifically referring to Syria and Lebanon. Hamas vowed to retaliate in kind if Israel began foreign attacks.
 
Israel apparently made good on its promise in September 2004, when Israeli security forces claimed responsibility for a car bombing in Damascus. Iz a-Din al-Sheikh Khalil, believed to be the leader of Hamas military operations outside of Palestinian territories, was killed in the explosion.
 
In January 2006, Hamas won Palestinian legislative elections, taking control of the Palestinian government. While initially cutting off all funding to the Hamas-led government, the U.S., E.U., U.N. and Russia subsequently sought to transfer funds to Palestinian elements while bypassing the Palestinian Authority.
 
On March 20, 2006, Hamas formed a new Cabinet within the Palestinian Authority. Tensions continued to rise in the Gaza Strip between Fatah and Hamas militants.
 
Under heavy international pressure in March 2007, Hamas and Fatah formed a Palestinian unity government. Despite the formal union, the rivals continued their struggle for control of the Palestinian government. That struggle culminated in Hamas's seizure of the Gaza Strip in mid-2007. Since that time, Hamas has continued to be involved in two conflicts: an external effort against Israel and its internal rift with Fatah.

Israel attacked what it called the Hamas terrorist infrastructure in the Gaza Strip in December 2008, then declared a cease-fire on Jan. 17, 2009.

Israel has blockaded Gaza since 2007, saying it needs to keep weapons out of the hands of Hamas so it cannot terrorize Israelis. The breach of the blockade in May 2010 by an aid flotilla resulted in the deaths of nine pro-Palestinian acitivists.

The Israeli security service Shin Bet said in June 2010 that Hamas and Islamic Jihad have more than 5,000 rockets (with more than 4,000 in the hands of Hamas alone) with ranges of up to 25 miles in the Gaza Strip.

1987
Hamas was formed as a Palestinian offshoot of the Muslim Brotherhood.
 
1989
Israeli authorities arrested Sheikh Yassin.
 
1991
Zaccaria Walid Akel set up the first cells of the Izz el-Din al-Qassam Brigades.
 
1994
Oct. 19: A Hamas suicide bomber detonated himself in a bus in Tel Aviv, killing 22.
 
1997
Yassin was freed from prison in exchange for the release of two Israeli agents who were being held in Jordan.
 
2000
September: The Al Aqsa intifada began after Likud Party leader Ariel Sharon visited the Temple Mount/Noble Sanctuary in Jerusalem.
 
2001
May 18: Four people were killed and 100 others injured outside the HaSharon shopping mall by a Hamas suicide bomber.
 
Aug. 9: Fifteen people were killed and more than 90 others wounded when a Hamas suicide bomber blew himself up in a crowded pizzeria in downtown Jerusalem.
 
Sept. 9: A suicide bomber killed three people and wounded 90 near the Nahariya train station in northern Israel.
 
Oct. 2: Hamas members infiltrated Gaza District, opened fire on residents and threw grenades into homes, killing two and wounding 15 others.
 
December: Israeli forces killed Yakub Adqeq, a 28-year-old Hamas leader, when he tried to avoid arrest in Hebron.
 
Dec. 4: The Bush administration froze the U.S. assets of the Texas-based Islamic Holy Land Foundation, saying the charity routinely provided funds to Hamas.
 
2002
July: Izz el-Din al-Qassam leader Salah Shehada was killed when an Israeli air force F-16 dropped a bomb on an apartment building in Gaza City.
 
2003
June 29: Hamas and Islamic Jihad agreed to a truce with the Israeli government as part of the U.S.-sponsored peace framework.
 
Aug. 19: A suicide bomber detonated himself in the Jewish orthodox neighborhood of Shmuel Hanavi in Jerusalem, killing at least 20. Hamas and Islamic Jihad claimed responsibility for the attack.
 
Aug. 20: Israeli helicopter gunships fired on a car in the Gaza Strip, killing Hamas political leader Ismail Abu Shanab. Immediately after the attack, Hamas and Islamic Jihad declared an end to the June cease-fire.
 
2004
Jan. 16: Israeli Deputy Defense Minister Zeev Boim said Israel would hunt down and kill Hamas founder Sheikh Ahmed Yassin in retaliation for an earlier suicide attack that killed four border guards at a Gaza Strip border crossing.
 
March 22: Sheik Ahmed Yassin was assassinated by Israeli helicopter gunships in a missile strike as he was leaving a mosque. Abdel Aziz Rantisi was chosen as Yassin's successor.
 
April 17: Abdel Aziz Rantisi was assassinated by Israeli gunships in a missile strike on his car. Mahmoud A-Zahar was chosen as Rantisi's successor.
 
May 18: Israel began a three-day operation in the Gaza city of Rafah to round up suspected militants and destroy tunnels used for smuggling arms from Egypt. Several Hamas members were captured or killed, including local military leader Khalid Abu Anza.
 
Aug. 31: Two Hamas suicide bombers exploded bombs on buses in the Israeli city of Be'er Sheva, killing 16.
 
Sept. 26: A car bomb in Damascus killed Iz a-Din al-Sheikh Khalil, a top Hamas military leader. Israeli security officials claimed responsibility.
 
2005
July 15: Israel retaliated against Hamas rocket strikes with airstrikes targeting Hamas members. The exchange signaled the end of an informal cease-fire that was agreed to in February by Israel and several Palestinian militant groups. Hamas vowed to respond to the airstrikes with more attacks.
 
July: Tensions flared between Hamas and Palestinian Authority security forces, resulting in several deadly skirmishes. The PA was attempting to assert control in Gaza and prevent Hamas from launching rockets at Israel.
 
Sept. 24: Hamas launched dozens of Kassam rockets into southern Israel. Prime Minister Ariel Sharon responded by ordering the Israeli military to use all necessary means to stop the attacks. Over the next week, the IDF carried out the orders with air strikes targeting Hamas leaders, a roundup of suspected militants in the West Bank and artillery fire into Gaza.
 
2006
Jan. 25: Hamas won 76 of 132 seats in Palestinian parliamentary elections, giving the group the right to form the next Cabinet. The U.S., E.U., U.N. and Russia subsequently threatened to withhold aid to the Palestinians if Hamas did not renounce violence and recognize Israel.
 
May 7: An alleged Hamas plot to assassinate Mahmoud Abbas was thwarted after he was tipped off by Israeli intelligence, according to London's Sunday Times. Intelligence sources said that Hamas' military wing had planned to kill Abbas at his office in Gaza. Spokesmen for both Hamas and Abbas denied the report.
 
May 8: Three Palestinians were killed and 10 wounded in clashes in southern Gaza between rival Hamas and Fatah gunmen.

May 17: Hamas deployed some 3,000 fighters in the Gaza Strip as part of a new security force. In response, about 1,000 Palestinians, including hundreds of police officers loyal to President Mahmoud Abbas, marched in the Gaza Strip in a show of strength against Hamas security forces. However, some police officers also backed Hamas, meeting with Palestinian Prime Minister Ismail Haniya and professing their loyalty to the Hamas-led government.
 
May 24: Palestinian gunmen killed one Hamas member and wounded four others in the Gaza Strip. As armed clashes stirred fears of civil war, the Hamas-led Palestinian government and Abbas' rival Fatah faction agreed on the same day to rein in their supporters.
 
June 25: Hamas members used a tunnel to attack an Israeli army post on the Gaza border, killing two soldiers and kidnapping another. Israel responded with a large-scale operation in Gaza to recover the soldier and arrested several high-ranking Hamas politicians.
 
Nov. 25: The Hamas-led Palestinian government committed itself to a cease-fire with Israel in the Gaza Strip.
 
2007
Jan. 5: Hamas gunmen killed seven members of the Fatah security services in the Gaza Strip. The deaths, which followed weeks of factional fighting, led to Fatah reprisal attacks on Hamas offices and vehicles.
 
Feb. 15: Palestinian President Abbas asked Prime Minister Haniyeh to appoint a new Cabinet. Abbas stressed that peace agreements with Israel should be observed.
 
March 17: The Palestinian legislature overwhelmingly approved a coalition Hamas-Fatah government. However, Israel balked at peace talks with the unity government because of Hamas' statements supporting the destruction of Israel.
 
March 19: An Israeli utility worker was shot and wounded near the Gaza border. Hamas claimed responsibility for the attack.
 
May 27: Israel vowed not to let up its attacks on Gaza. Hamas continued its rocket launches against Israel.
 
June 11: The Israeli Security Cabinet endorsed efforts by Egypt to obtain a truce in Gaza, noting that its army was ready for military action if negotiations failed.
 
June 14: Hamas seized control of Gaza, defeating Fatah forces during a week-long battle. Abbas dissolved the Hamas-led unity government and appointed a new, Fatah-supported administration. Salam Fayyad, an economist, was appointed to lead the new emergency government. Israel and the new Palestinian government opened formal contacts. Israel said it would tighten its blockade of Gaza.
 
June 16: The United States promised to lift its ban on aid to the new Palestinian emergency government.
 
Nov. 27: U.S. Secretary of State Condoleza Rice conducted a conference in Annapolis, Md. Representatives from Israel and the Palestinian Authority expressed support for negotiating a two-state agreement by the end of 2008.
 
Dec. 12: Israel and the Palestinian Authority began talks related to West Bank settlements and Palestinian security concerns.
 
2008
Jan. 23: Gaza militants used explosives to breach the border wall in Rafah, a Palestinian town in the Gaza Strip. Thousands of Palestinians passed through the breach into Egypt to procure goods that could not be obtained in Gaza as a result of the Israeli blockade. The border remained opened for several days before it was sealed again.
 
Feb. 26: Israel launched a five-day offensive in Gaza after Palestinian militants fired around 70 rockets and mortar shells into Israeli territory. More than 110 Palestinians were killed in the Israeli offensive.
 
March 23: Yemen brokered a temporary agreement between Fatah and Hamas to resume direct talks, but negotiations broke down over Hamas's refusal to relinquish control of Gaza.
 
June 17: Israel and Hamas signed a cease-fire agreement brokered by Egypt in an effort to end more than a year of violence. Cairo also indicated that it would step up its efforts to stop the smuggling of arms through Egypt into Gaza.
 
September: The Kuwaiti newspaper Al Rai reported that the Hamas leader Khaled Meshal had relocated to Sudan from Syria at the request of the Syrian government. Hamas denied the reports.
 
Sept. 30: Hamas and Fatah leaders pledged to seek accommodation at pending talks sponsored by the Egyptian government. A high-level Egyptian representative met separately with each side. More preliminary talks were scheduled with the Fatah and Hamas prior to talks scheduled for Nov. 4 in Cairo.

Dec. 19: The cease-fire between Israel and Hamas expired.

Dec. 24: Militants in Gaza fired rockets at Israel.

Dec. 27: Israel launched retaliatory airstrikes on Gaza, killing at least 229 Palestinians, signifying the start of Operation Cast Lead.

Dec. 28: Israel launched airstrikes on Hamas targets in the Gaza Strip, hitting the Islamic University and smuggling tunnels. An emergency U.N. Security Council session considering an Arab resolution for a cease-fire adjourned without a vote.

2009
Jan. 1: Israeli forces killed a Hamas leader, Nizar Rayyan, in an airstrike on his Gaza home.

Jan. 3: Israel launched a ground offensive into the Gaza Strip with tanks and infantry. A week later, Khaled Meshaal, the leader of Hamas, said Israel was perpetrating a "holocaust" in Gaza. The Hamas leader said there would be no consideration of a cease-fire until Israel ended its operations.

Jan. 14: Rockets launched from Lebanon struck Israel for the second time in a week. In an effort to end the hostilities, U.N. Secretary General Ban Ki-Moon arrived in Cairo and called again for an immediate cease-fire between Israel and Hamas. Egypt initiated a dialogue with Hamas aimed at facilitating a cease-fire.

Jan. 17: Israel declared a unilateral cease-fire, ending its military operation.

Jan. 18: Hamas instituted its own cease-fire. A Hamas official contended that 5,000 homes, 16 government buildings and 20 mosques were destroyed and 20,000 houses damaged in the three-week war.

June 25: Hamas Political Bureau Chief Khalid Mish'al dismissed a proposal issued by Israeli Prime Minister Benjamin Netanyahu for a two-state settlement that called for disarming Palestine. He asserted that the minimum terms for a settlement would be a Palestinian state with Jerusalem as its capital, full sovereignty, removal of settlements and the right of return for fefugees. There was no alternative to continued armed struggle, he said.

2010
Feb. 11: During incidents spread over two days, Palestinian militants from the Hamas-run Gaza Strip launched attacks against Israel involving the use of automatic weapons and explosives planted near the Israel-Gaza border, as well as within Israeli territory.

March: Between March 11 and March 18, numerous attacks launched from Gaza struck facilities in Israel.

March: 14: Israeli security forces reported the arrest of a senior Hamas official after a raid in Ramallah, the seat of the Palestinian government in the West Bank. The Israeli military said the arrested militant, Maher Audi, was a founder of Hamas in the West Bank, and was responsible for the deaths of 10 Israelis.

March 18: Israel's permanent representative to the United Nations, Gabriela Shalev, expressed "grave concern" about the recent spate of attacks on Israel launched from Gaza. Shalev urged the U.N. to "condemn Hamas' ongoing terrorist attacks, as well as its tactics that endanger Israeli and Palestinian civilians."  Shalev further stated that "given such realities and the ongoing nature of Hamas's murderous attacks," Israel would "exercise its right of self-defense pursuant to international law."

March 27: Israeli planes had bombed a convoy of trucks near the Egyptian border in Sudan in January. Israel said the convoy was believed to be carrying arms to be smuggled into Gaza, which may have originated in Iran.

May 29: Rocket attacks launched from Gaza struck Israel less than a day after the Israeli government and the Palestinian Authority agreed to the resumption of third-party negotiations. The Israeli air force, in turn, targeted a smuggling tunnel and a non-operational Gaza airport. Hamas had opposed the resumption of talks. According to the Israeli military, nearly 50 rockets landed in Israeli territory since the beginning of 2010.

May 31: Israel intercepted a flotilla of vessels trying to bring humanitarian aid to Gaza and breaching the blockade. The mission was sponsored by the Free Gaza Movement. Nine pro-Palestinian activists were killed. Hamas continued to call for an end to the blockade.