Chequers (ˈtʃɛkərz ) is the country house of the Prime Minister of the United Kingdom. A 16th-century manor house in origin, it is near the village of Ellesborough, halfway between Princes Risborough and Wendover in Buckinghamshire, at the foot of the Chiltern Hills, north-west of central London. Coombe Hill is northeast. Chequers has been the country home of the serving Prime Minister since 1921 after the estate was given to the nation by Sir Arthur Lee by a Deed of Settlement, given full effect in the Chequers Estate Act 1917. The house is listed Grade I on the National Heritage List for England. The name "Chequers" may derive from an early owner of the manor of Ellesborough in the 12th century, Elias Ostiarius (or de Scaccario). The name "Ostiarius" meant an usher of the Court of the Exchequer and scacchiera means a chessboard in Italian. Elias Ostiarius's coat of arms included the chequer board of the Exchequer, so the estate may be named after his arms and position at court. The house passed through generations of the Scaccario family (spelt many different ways) until it passed into the D'Awtrey family, whose name was eventually anglicised to Hawtrey. Alternatively, the house could have been named after the chequer trees (Sorbus torminalis) that grow in its grounds. There is a reference to this in the book Elizabeth: Apprenticeship by David Starkey, which describes the early life of Elizabeth I. William Hawtrey built the current mansion around 1565, and it may have involved the reconstruction of an earlier building. A reception room in the house bears his name today. Soon after its construction, Hawtrey acted as a custodian at Chequers for Lady Mary Grey, younger sister of Lady Jane Grey and great-granddaughter of King Henry VII. Lady Mary had married without the monarch's consent, and as punishment was banished from court by Queen Elizabeth I and kept confined. Lady Mary remained at Chequers for two years. The room where she slept from 1565 to 1567 remains in its original condition.