The Occupation of Iraq is characterized by a large United States military deployment on Iraqi territory, beginning with the U.S.-led invasion of the country in March 2003 which overthrew the Ba'ath Party government of Saddam Hussein and ending with the departure of US troops from the country in 2011. Troops for the invasion came primarily from the United States, the United Kingdom and Poland, but 29 other nations also provided some troops, and there were varying levels of assistance from Japan and other countries.