Gilkes was born in
Leominster, a son of William Gilkes, a chemist. He was educated at
Shrewsbury School and went on to
Christ Church, Oxford, from where he received a
First Class Honours degree in
Literae Humaniores in 1872, having achieved a first class in
Mods in 1870. He was promoted to
MA in 1885. On 19 May 1892 Gilkes married Millicent Mary Clarke, a daughter of Bennett Michell Clarke, and the sister of three brothers who attended
Dulwich College. They had four sons, all of whom went to Dulwich College, and one daughter. One of his sons,
Christopher, would later become Master of Dulwich College. Another son,
Humphrey, became a doctor and was one of four soldiers to be awarded the
Military Cross on four occasions in the First World War. ==Career==