A portrait of Ayatollah Khomeini on a building shelled by the Israeli military
in southern Lebanon in 2006 [GALLO/GETTY]
 
Iran and its Arab neighbours have maintained a wary, yet stable relationship throughout the 20th century. However, relations deteriorated rapidly during and after the Islamic Revolution in 1979.
Neighbours such as Iraq, Kuwait, Saudi Arabia and Bahrain accused Iran of inciting their Shia minorities. When Iraq invaded Iran in 1980, Saddam Hussein, Iraq's former president, repeatedly said he was fighting on behalf of Arab states against "Persian expansionism".
Since the US-led invasion of Iraq in 2003, relations between Iran and the Arabs plummeted even further. In 2005, as sectarian war appeared to threaten Iraq with civil war, Saud al-Faisal, Saudi Arabia's foreign minister, said US policy in the country was benefiting Iran.
"We fought a war together to keep Iran out of Iraq after Iraq was driven out of Kuwait. Now we are handing the whole country over to Iran without reason," al-Faisal said in 2005.
Relations between Iran and the Shia Hezbollah movement of Lebanaon on the one hand, and Egypt, Jordan, and Saudi Arabia, on the other, reached boiling point in July 2006 when Tehran accused the Arab states of allowing Israel to invade Lebanon.
In late 2007, relations between Iran and the Arabs suddenly changed with foreign ministers exchanging visits to better ties and sign business and security pacts.
In the years following the defeat of Iraqi forces in Kuwait, the US adopts a dual containment policy targeting Iran and Iraq. Nevertheless, Iranian leaders begin a new wave of diplomacy to improve relations with Arab governments.
Once considered a hostile neighbour, Iran has seen its influence grow in the political spectrum of the Middle East.
In recent years, it has supported movements countering what it calls US interventionist policy.
Iran is known to support Hezbollah in Lebanon, Hamas in the Gaza Strip, and according to the US military, Shia militias in Iraq.
As a result, Iran is now regarded a major player in the geopolitics of the Middle East.
The inclusion of Mahmoud Ahmadinejad, its president, in the meeting of the GCC in 2007 reflected a concerted effort on the part of Arab states to recognise Iran's influence as a rising power.
More recently, however, ties between some Arab states and Iran deteriorated after the Israeli war on Gaza in December 2008. Iran accused Egypt and Jordan of standing by and co-operating with Israel's closure of the Gaza Strip
Timeline: Arabs and Iran
1969: Iran drops its claim on Bahrain.
1971: Iranian forces occupy three islands, including the strategic island of Abu Musa at the entrance of the Strait of Hormuz, claimed by both Tehran and the United Arab Emirates. The UAE agrees to share control of Abu Musa but continues to call for the return of the other two islands - the Lesser Tunb and the Greater Tunb.
March 1975: Iraq and Iran sign an agreement mediated by Algeria ending all outstanding border disputes. Iraq makes territorial concessions, chiefly relinquishing demands for the Shatt-al-Arab waterway shared by both countries in the Gulf. In return, Iran stops supplying Kurdish separatists with arms and money for their war against Baghdad.
October 1978: In further observance of the 1975 agreement, Iraq's government asks Ayatollah Khomeini, the leading Iranian cleric, to leave Najaf after spending 14 years in exile in the country. Khoemini leaves for Kuwait where he is denied entry and diverted to Paris.
 
January 1979: Mohammed Reza Pahlavi, the Shah of Iran is ousted from power. Anwar Sadat, Egypt's president, angered Khomeini by providing a home for the exiled shah. Iran then severed all ties with Egypt.
February 1979: Khomeini returns to Tehran and is installed as leader and founder of the Islamic Republic of Iran.
November 1979: Iranian students storm the US embassy and take several Americans hostage. The siege lasts 444 days and comes to be known as the Iran Hostage Crisis.
September 1980: Khoemini calls for Iraq's Shia to rise up against the Saddam Hussein government. Saddam responds by annuling the 1975 Algiers Agreement. Both countries shell each others' borders. Iraqi military forces invade on September 22.
Saddam, says he is fighting Iran on behalf of other Arab states, who viewed the country as a threat to stability.
Almost all Arab countries, except Syria and Libya, support Iraq logistically and financially.
1980: The UAE submits its claims on Abu Musa to the UN. In the same year, Qatar, UAE, Kuwait, Oman, Saudi Arabia, and Bahrain form the Gulf Co-operation Council in response to Iranian threats.
October 1981: Anwar Sadat is assassinated by Islamic Jihad members. Iran symbolically renames a Tehran street in honour of Khaled el-Islambouli, Sadat's assassin.
July 1987: More than 400 Iranian pilgrims are killed during the Hajj in Mecca when they clash with Saudi security forces during an anti-Iraq and anti-US demonstration.
July 1988: While protecting Kuwaiti oil tankers in the Gulf, US Navy cruiser Vincennes shoots down an Iranian civilian airliner killing 290 passengers.
August 1988: Iran and Iraq sign a UN-brokered ceasefire ending their war. Some two million soldiers and civilians are killed and wounded during the eight-year conflict.
July 1989: Saudi authorities execute 16 Kuwaiti Shias alleging they plotted a number of bombings which killed two pilgrims in Mecca. Riyadh blames Tehran for the attacks.
August 1990: Iraq invades Kuwait. Iranian policy-makers opt for non-involvement.
January 1991: Saddam Hussein revisits the Algiers agreement and concedes the Shatt-al-Arab waterway to Iran.
April 1992: Iranian forces take full control of Abu Musa.
1996: Iran begins to build a runway in Abu Musa and a power station on Greater Tunb.
1997: Mohammad Khatami, considered a reformist among Iran's ruling clergy, is elected president in a landslide win. He immediately embarks on a foreign policy agenda to mend ties with the US and Arab neighbours. Exchange of Iranian and Iraqi POWs is quickened.

November 1999: The GCC fully supports and backs the UAE's diplomatic efforts to regain control of Abu Musa and other contested islands.
2001: Iran and Saudi Arabia sign a mutual security accord.

Source: Al Jazeera