It is thought to have been set aside as Royal hunting land when the Anglo-Saxon kings had a palace at Brill and church in Oakley, in the 10th century and was a particularly favoured place of Edward the Confessor, who was born in nearby Islip.
King Henry II (reigned 1154–1189) prepared a map of the forest at the time which is an invaluable tool in helping define its ancient boundaries; however, his purpose for drawing up the map was to divide the forest amongst his nobles.
Again, the map was drawn up under the aegis of the Crown as an audit to what revenue could be made from selling off the forest.
Today the name refers to the area of Buckinghamshire and Oxfordshire where the forest was at the time of King Henry II, covering 400 km².
Aerial spraying of pesticides occurring up until the late 1960s:firstly DDT to control Hylobius abietis then 2,4,5-T to clear broad-leafed plants (including oak saplings) before planting commercial pine stands.