The Great Offensive (Turkish: Büyük Taarruz) was the largest and final military operation of the Turkish War of Independence, fought between the Turkish Armed Forces loyal to the government of the Grand National Assembly of Turkey, and the Kingdom of Greece, ending the Greco-Turkish War. The offensive began on 26 August 1922 with the Battle of Dumlupınar. The Turks amassed around 98,000 men, the largest number since the beginning of the war, to begin the offensive against the Greek army of approximately 130,000 men. From 31 August to 9 September, the front moved a distance of 300 km (190 mi) as the Greek troops retreated. The Turkish army lacked motorized vehicles; its forces consisted of infantry and cavalry units, and logistical support was provided by a supply system based on ox carts.
The Turkish troops reached the sea on 9 September with the capture of İzmir. The operation ended on 18 September 1922 with the capture of Erdek and Biga. The staggering defeat caused great dissent within the Greek army and a general loss of morale, which led to unwillingness to continue fighting. On top of this, numerous Greek divisions had been encircled and destroyed as effective fighting units, which meant that the Greek army had lost its offensive capabilities and was unable to organize a controlled retreat, leading to numerous Greek POWs.