Open warfare was declared by Saddam Hussein on Sept. 22, 1980, when Iraqi armed forces invaded western Iran along the countries’ joint border, though Iraq claimed that the war had begun earlier that month, on September 4, when Iran shelled a number of border posts. The roots of the war lay in a number of territorial and political disputes between Iraq and Iran. Iraq wanted to seize control of the rich oil-producing Iranian border region of Khuzestan territory inhabited largely by ethnic Arabs over which Iraq sought to extend some form of suzerainty. Iraqi president Saddam Hussein wanted to reassert his country’s sovereignty over both banks of the Shatt al 'Arab, a river formed by the Tigris and Euphrates rivers that was historically the border between the two countries.The total number of combatants on both sides is unclear,but both countries were fully mobilized. Also most men of military age were under arms. The number of casualties was enormous but also uncertain. Estimates of total casualties range from 1,000,000 to twice that number. The number of casualties on both sides was maybe about 500,000, with Iran suffering the greater loss. It is estimated that between 50,000 and 100,000 Kurds were killed by Iraqi forces during the series of campaigns code-named Anfal that took place in 1988. The Iran-Iraq War ended in July of 1988 as a stalemate.