Various.

Hillingdon parish included a number of freeholds outside of the local manor of Colham. In 1636 there were 35 freeholds in Colham manor, covering more than 300 acres, mostly on the edge of the heath. From the 17th century a number of these houses were owned by persons of importance, and were noted for pleasure gardens. Hillingdon House had the largest estate, which was owned by the Cox family after 1810. The estate was broken up in 1915 when it comprised over 500 acres including land in Harefield and Ruislip.

From: 'Hillingdon, including Uxbridge: Manors and other estates', A History of the County of Middlesex: Volume 4: Harmondsworth, Hayes, Norwood with Southall, Hillingdon with Uxbridge, Ickenham, Northolt, Perivale, Ruislip, Edgware, Harrow with Pinner (1971), pp. 69-75 (available online).