Modern Iraq includes the territory known in ancient times as Mesopotamia. This region, consisting of the land between the Tigris and Euphrates rivers, was one of the first centers of civilization. The Sumerians, Akkadians, Babylonians, Assyrians, and Chaldeans established great empires in this area.
| Important dates in Iraq | |
| 3500 B.C. | The world's first known civilization developed in Mesopotamia, now Iraq. |
| 539 B.C. | The Persians conquered Mesopotamia. |
| 331 B.C. | Alexander the Great seized Mesopotamia. |
| c. A.D. 224 | The Sasanian dynasty of Persia conquered Mesopotamia. |
| 637 | Arab Muslims overthrew the Sasanians. |
| 1258 | The Mongols invaded Mesopotamia. |
| 1500's | The Ottoman Empire began to establish control over Mesopotamia. |
| 1920 | The League of Nations gave the United Kingdoma mandate (order to rule) over Mesopotamia. |
| 1932 | The British mandate ended, and Iraq became independent. |
| 1958 | Army officers overthrew the Iraqi government and declared the country a republic. |
| 1968 | The Baath Party took control of Iraq's government. |
| 1973 | The Iraqi government completed its take-over of foreign oil companies in Iraq. |
| 1980 | Iraq declared war on Iran. |
| 1988 | Iraq and Iran agreed to a cease-fire. |
| 1990 | Iraq invaded Kuwait. |
| 1991 | A coalition of 39 nations, organized mainly by the United Nations and the United States, defeated Iraq in the Persian Gulf War of 1991. |
| 2003 | Forces led by the United States overthrew the Baath Party government of Saddam Hussein in the Iraq War. |
| 2005 | Iraqis elected a permanent government under their new constitution. |
In 539 B.C. Cyrus the Great conquered Mesopotamia for the Persian Empire. Alexander the Great's conquest in 331 B.C. led to the rule of the Seleucids, a Macedonian dynasty. Later the region was ruled by two Persian dynasties; the Parthians ruled from 130 B.C. to 226 A.D. , and the Sassanids ruled from 226 to 640.
Mesopotamia was conquered by Arabs about 640, and its people became Arabic-speaking Muslims. Under the Abbasid Caliphate, 750–1258, the region enjoyed great prosperity. After repeated devastation by Mongols, Turks, and Persians, however, Mesopotamia's economy was ruined. The Ottoman Turks gained permanent possession of the area in 1638.
