Hiram Irwin was the son of David and Margaret Irwin. He was born in 1883 at Ballymaguire. He was the fourth of eight children, all born in the Coagh-Stewartstown area. They were a farming family. Hiram enlisted in the North Irish Horse in 1909. He Hiram Irwin called up for active service with the North Irish Horse on 5th August 1914, two days after war was declared. He saw action in the retreat from Mons. He became part of the bodyguard to Sir John French. He later transferred to the Corps of Hussars.