In August 1914, it served in numerous overseas theatres including Belgium and northern France. By 1918, a total of 1.5 million people had been mustered in seven Indian Expeditionary Forces. Over one million served overseas in Europe, Africa, Palestine and Mesopotamia: 800,000 soldiers and 400,000 labourers. Fifty thousand were killed or died of wounds.

After 1919, and the growing fear that Indian nationalism would undermine the army’s effectiveness, Indian troops continued to be deployed overseas and in support of the civil authorities in India.

When war broke out in 1939 the Indian Army was just under 200,000-strong. By August 1945 it had reached over 2.5 million volunteers, the largest in history.

Their most important role remained the defence of India itself. Despite sweeping Japanese victories in Malaya, Singapore and Burma, Indian forces halted this onslaught in May 1942. But the sacrifice was heavy. Over 87,000 were killed during the Second World War.