The Palladian Palace was built in 1780 by Barlow Trecothick, from Boston, Massachusetts in the colonial Province of Massachusetts Bay, who returned to England and became an MP and Lord Mayor of the City of London in 1770. After his death without heirs, his nephew James Ivers (later Trecothick), also of Boston, continued his uncle's work and had the grounds laid out by Capability Brown. The estate was sold and eventually, as Croydon Palace became too inconvenient and unsanitary, the Addington house and part of the estate was bought for the Archbishops of Canterbury as a country residence. The last Archbishop to use it was Archbishop Benson. Around 1805 parts of the estate covering what is now New Addington were sold to John Cator of Beckenham Place, including Castle Hill Farm. Cator left this to George and Henry Sparkes in his Will in 1806, citing "Addington recently acquired from ... Trecothick" but the land appears as part of the Cator estates in an 1825 Private Act of Parliament allowing the Cators to sell the land, as John Barwell Cator was transferring the main estate holdings to Woodbastwick in Norfolk. (sources, Will of John Caor, 1825 Private Act of Parliament)