It was the first military operation of the Mesopotamian Campaign of World War I which was carried out to protect the British Empire's oil supplies in the Persian Gulf.

[1] The British assigned Indian Expeditionary Force D (IEF D) which consisted of the 6th (Poona) Division led by Lieutenant General Arthur Barrett, with Sir Percy Cox as Political Officer.

The initial landing force was a contingent of Royal Marines from HMS Ocean and British Indian troops of the 16th (Poona) Brigade under Walter Sinclair Delamain.

[2] The British sloop HMS Odin shelled the Turkish positions near the old fortress of Fao, silencing the enemy batteries and clearing the way for the landing force.

[4][5] The landing and capture of Fao was a strategic blunder for the Ottomans from which they would never truly recover as evidenced by the subsequent string of defeats suffered by the Empire at the hands of the British in the following year.