[1] Henry Gage was born in Montreal, the eldest son of General Thomas Gage, military leader of British Forces at the beginning of the American Revolution, and Margaret Kemble.

He was also a captain in the Sussex yeomanry (1798), a lt.-colonel in 1798 and Colonel of the South Pevensey Volunteers in 1803.

In 1789 he married his cousin, Susanna Maria Skinner, a descendant of the Delancey family.

Both Henry and his wife shared extensive Dutch roots in British North America, including the Schuyler family and Van Cortlandt family, among others.

The historic letters and documents from this inheritance were later donated to the Sussex Archaeological Society of Lewes.