Moated manor house first mentioned in 1396. Replaced Sudbury Court as the Archbishops of Canterbury main Middlesex residence during C14 and C15.
Headstone House formed part of the manor of Harrow, and not mentioned as a separate estate until the 14thc. The earliest mention of the manor of Harrow is 822 AD., when Wilfred Archbishop of Canterbury purchased Harrow and other lands to restore them to the church of Canterbury, from which they had been taken by Cenwulf King of the Mercians. The first actual mention of Headstone as a separate manor was in 1396, when it consisted of a well-built house and 201 acres of land. Court Rolls from 1278-1645 relating to the see of Canterbury say: In 1451 Headstone was in the occupation of Wm and Richard Redyng who appear to have been farmers, and in 1466 William Page held it in the same manner. In 1483 Wm. Redyng is returned as occupying it, and in 1488 & 1490. In 1503 it was in the hands of Isabella, widow of Wm Redyng while Richard Redyng renders an account of the estate in 1543. In this year all the lands in Harrow, and other counties went to Henry VIII in exchange for other estates. In 1546 the King granted them to Sir Edward Dudley and they remained in his family till 1630 eventually passing to Simon Revse, Sir W Bucknell, John Askell Bucknell, Hon Wm Grinston, Mr Bucknell Estcourt and is now the property of Wm Bush Copper Esq. The formation of a moated dwelling probably dates from 1344, simply a fortified dwelling for the occasional residence of the Archbishop of Canterbury. The Great Barn: probably erected 1458-1543 measures 147'8" external length; by 38'8" wide. It is built entirely of oak, some of the timbers being 14" square. The smaller erections, now converted into stables, appear to be about the same date as the large barn. The whole house was fearfully modernised at the beginning of the 19th c