The son of James Long and his wife Susan Strangways, he was born at Athelhampton and baptised at Melbury House, Dorchester, Dorset in 1682.
[1] He married Henrietta Greville on 6 June 1702 at St Martin in the Fields, Westminster, London.
She was the daughter of Fulke Greville, 5th Baron Brooke and his wife Sarah Dashwood, and a descendant of the Earl of Bedford.
He used the inheritance to purchase more land in Dorset, adjacent to Athelhampton, in the manors of Burleston and Southover.
His daughter Susanna created a scandal by marrying her mother's gardener in 1732, as noted in his diary by Viscount Perceval (related distantly by marriage to the Longs).