The name, which means "soil", was first recorded in 1195 as "Slo". It first seems to have applied to a hamlet between Upton to the east and Chalvey to the west, roughly around the "Crown Crossroads" where the road to Windsor (now the A332) met the Great West Road. The Domesday Survey of 1086 refers to Upton, and a wood for 200 pigs, worth £15. During the 13th century, King Henry III had a palace at Cippenham. Parts of Upton Court were built in 1325, while St Mary the Virgin Church in Langley was probably built in the late 11th or early 12th century, though it has been rebuilt and enlarged several times.