The son of
Major-General Sir Edmund Leach of Corston House,
Pembrokeshire, he was educated at
Uppingham School and the
Royal Military College, Sandhurst, where he won the Sword of Honour. His brother,
William, was a
Royal Navy officer and
first-class cricketer. He was commissioned into the
Northumberland Fusiliers as a
second lieutenant on 2 May 1891, and was promoted to
lieutenant on 8 February 1893. He was
adjutant of the 4th (
Volunteer) Battalion
Yorkshire Regiment from 1 May 1899. He was promoted to
captain on 27 January 1900, and served with distinction as a Special Service Officer for Mounted Infantry in the
Second Boer War in
South Africa. Following the end of that war in June 1902, he left
Cape Town on the SS
Canada returning to
Southampton in late July, and was back in a regular commission with his regiment three months later. He was promoted to
major in 1904, and served as Military Secretary to the
Governor of Gibraltar from 1905 to 1910. In 1908 he transferred to the
South Wales Borderers and in 1912 he took command of the 2nd Battalion, being promoted
lieutenant-colonel the following year. ==First World War==