The siege of Kut Al Amara (7 December 1915 – 29 April 1916), also known as the first battle of Kut, was the besieging of an 8,000 strong British Army garrison in the town of Kut, south of Baghdad, by the Ottoman Army. In 1915, its population was around 6,500. Following the surrender of the garrison on 29 April 1916, the survivors of the siege were marched to imprisonment at Aleppo, during which many died. Historian Christopher Catherwood has called the siege "the worst defeat of the Allies in World War I". Ten months later, the British Indian Army, consisting almost entirely of newly recruited troops from Western India, conquered Kut, Baghdad and other regions in between in the Fall of Baghdad.
The 6th (Poona) Division of the Indian Army, under Major-General Charles Townshend, had fallen back to the town of Kut after retreating from Ctesiphon. The British Empire forces arrived at Kut around 3 December 1915. They had suffered significant losses, numbering only 11,000 soldiers (plus cavalry). General Townshend chose to stay and hold the position at Kut instead of continuing the march downriver towards Basra. Contained within a long river loop, Kut offered a good defensive position although supply lines from distant Basra were stretched.
The pursuing Ottoman forces under Halil Pasha arrived on 7 December 1915. Once it became clear the Ottomans had enough forces to lay siege to Kut, Townshend ordered his cavalry to escape south, which it did, led by Lieut. Colonel Gerard Leachman. The Ottoman forces numbered around 11,000 men and were increasing steadily with additional reinforcements arriving constantly. They were commanded by the respected but elderly German general and military historian Baron von der Goltz. Goltz knew the Ottoman army well, as he had spent 12 years working on modernizing it, from 1883 to 1895. After three attacks in December, Goltz directed the building of siege fortifications facing Kut. He prepared for an attack from Basra, using the Tigris River, by building defensive positions further down the river designed to cut off a river-borne relief.