Thanks hanes teulu
If he was 17 on 4 Dec 1816 (trial) and transported aged 18 on
26 April 29 March 1817, and assuming these entries are correct, he must have been born between 5 December and
26 April, 29 March and perhaps that's why researchers think he was William Ward, born 9 March and baptised 14 April 1799 at the Old Jewry Church.
If his parents (William and Ann Catherine nee Hennell) lived at Gee's Court, maybe they're not the wealthy couple that davisd think was related to the Hennell blacksmiths? All I coudl find is that they were married in 1795 in Edmonton, London, according to one transcript on FamilySearch. Is this correct (Ancestry, FindMyPast)? And was William the only son?