In September 1676 William Penn bought Warminghurst from Henry Bigland for £4,450, a mansion in the parish of the same name, located between Thakeham and Ashington. It was here between 1680 and 1682 that William worked on the Frame of Government for Pennsylvania, which later became the basis for the colony’s Constitution and influenced the American Declaration of Independence less than a century later.

Warminghurst remained Penn’s principal family home for over 30 years; his family remained at the house during Penn’s journey to the New World in 1682-1684 and whilst Penn moved home in 1696, he regularly visited his children William junior (Billy) and Letitia, and grandchildren who lived at the house until it was sold in 1707.