Chesham is a market town and civil parish in Buckinghamshire, England, United Kingdom, 11 miles (18 km) south-east of the county town of Aylesbury, about 26 miles (42 km) north-west of central London, and part of the London commuter belt. It is in the Chess Valley, surrounded by farmland. The earliest records of Chesham as a settlement are from the second half of the 10th century, although there is archaeological evidence of people in this area from around 8000 BC. Henry III granted a royal charter for a weekly market in 1257.