Background
Thornycroft was born in London, the son of Sir John Thornycroft and Dorothy, daughter of Sir John Howel.
Thornycroft was born in London, the son of Sir John Thornycroft and Dorothy, daughter of Sir John Howel.
He was educated at Street John"s College, Cambridge and Gray"s Inn and practiced as a barrister in Oxford.
He served as High Sheriff of Oxfordshire in 1701. He was created a baronet, of Milcombe, Oxfordshire in the Baronetage of England, on 12 August 1701. Soon after he had been made a baronet he presented a petition to the Lords of the Treasury, asking to be excused from paying The Crown the £1,095 sum expected in return for his honour.
He was excused payment.
His wife"s family owned the estate at Milcombe. Together they had five children, two of whom died young.