Pritchard was the son of Colonel Hurlock Pritchard, CSI, of Camberley, and was educated at Charterhouse School. He was commissioned into the Royal Engineers in 1891. He took part in the Fourth Anglo-Ashanti War in 1895 and was then transferred to the Egyptian Army in 1896 taking part in the Siege of Khartoum the following year. He was awarded the DSO for service in the Sudan.