Born at Eastbourne, Sussex, 1 December 1850, the eldest child and only son of Dr Robert Colgate, medical practitioner, and his wife,* née* Argles. He was educated at University College School in London and at University College Hospital, and took a postgraduate course at Vienna. He graduated at the University of London with honours at the MB examination and was awarded the gold medal at the BS. He practised at Eastbourne, where he was successively medical officer, surgeon, and consulting surgeon to the Princess Alice Memorial Hospital, and during the European war received a commission as lieutenant-colonel, RAMC, having previously been active as a volunteer. He married Ethel Dobell York (d. 1914) in 1880 and by her had a son, who died of wounds in 1916, and two daughters; Lady Holland, first wife of Sir Eardley Lancelot Holland, MD, FRCS, and Mrs Stanham, wife of Colonel H S Stanham, RA. He died at 19 St Anne's Road, Eastbourne on 7 November 1940. Active in craft masonry he was a Past Grand Deacon in the United Grand Lodge of England. He left £500 to University College Hospital.