In 1777 he married Susanna, widow of Edmund Bastard of Kitley, Devon, and sister of Sir Thomas Crawley-Boevey, baronet.
He was born in 1746 in Harley Street, City of Westminster in London, England and was the son of Robert Hyde Page (d. 1764), also a military engineer, and Elizabeth, daughter of Francis Morewood.
Thomas Hyde Page attended the Royal Military Academy, Woolwich, receiving a gold medal from King George III.
Page went with the corps of engineers to North America and distinguished himself in service to General Pigott at the Battle of Bunker Hill on 17 June 1775, where he was severely wounded.
In England, for the next few years he was the commanding royal engineer of the eastern coastal district and supervised the refurbishment of defences at Dover, Chatham, Tilbury, Gravesend, Sheerness, and Landguard Fort.
His expertise was still in demand and was made the chief consulting engineer in the improvement of the port of Dublin, of Wicklow harbour, of the inland navigation of Ireland, and of the Royal, Shannon and Newry canals.