British First Army

First Army
Emblem of the British First Army (1942–43)
Active	First World War 1914–1918 Second World War 1942–1943
Country	United Kingdom
Branch	British Army
Type	Army
Size	Field army
Engagements	World War I Western Front World War II Operation Torch Tunisia Campaign
Commanders
Notable commanders	Douglas Haig Sir Henry Rawlinson Kenneth Anderson

The First Army was a formation of the British Army that existed during the First and Second World Wars. Despite being a British command, the First Army also included Indian and Portuguese forces during the First World War and American and French units during the Second World War.

The First Army was part of the British Army during the First World War and was formed on 26 December 1914 when the corps of the British Expeditionary Force were divided into the First Army under Lieutenant-General Sir Douglas Haig and the Second Army under Horace Smith-Dorrien. First Army had the Ist, IVth and the Indian Corps under command. The First Army suffered reverses at Vimy Ridge in May 1916 and at Fromelles the following month. From 1917, the First Army also included the Portuguese Expeditionary Corps. The First Army took part in the 1918 offensive that drove the Germans back and virtually ended the war.

The British First Army was reformed during the Second World War. It was formed to command the American and British land forces which had landed as part of Operation Torch, the Allied invasion of French North Africa, in Morocco and Algeria on 8 November 1942. It was commanded by Lieutenant-General Sir Kenneth Anderson. The First Army headquarters was formally activated on 9 November 1942 when Anderson arrived in Algiers to assume command of the redesignated Eastern Task Force.