The earliest man-made structure in Maritime Greenwich is the buried remains of a Romano-Celtic shrine. It is on the high ground on the east of the Park, just south of Vanbrugh Castle.
It may have been part of a military post beside the old London to Dover road, which ran at that time through the Park. Coins found there suggest that the shrine was built in the 1st century AD and remained in use until the Romans left Britain in the 4th century.
The next evidence of habitation is a group of 31 Anglo-Saxon burial mounds, dating from the 6th century, on the hill west of the Observatory.
In AD 871 King Alfred the Great inherited Greenwich and in 918 his daughter, the widowed Countess of Flanders, presented it to the Abbey of St Peter at Ghent.
Early in the 11th century Greenwich was briefly occupied by Viking raiders – to whom it probably owes its name ('green place') and its patron saint, Alfege, Archbishop of Canterbury. Vikings murdered him at Greenwich in 1012 and he was buried where the parish church of St Alfege now stands.
In 1414 the manor of Greenwich reverted from the Abbey of Ghent to King Henry V. In 1426 it passed to his half-brother, the soldier and scholar Duke Humphrey of Gloucester, who built a house called 'Bellacourt' on the river's edge.
Its foundations, now under the Grand Square of the Old Royal Naval College, show it was originally a rectangular building about 21 metres (70 feet) long and on two floors.
In 1433 Humphrey first enclosed the Park with a fence and built a tower where the Royal Observatory now stands. On his death in 1447 Greenwich returned to royal ownership - that of Queen Margaret of Anjou, wife of Henry VI (who had imprisoned and possibly murdered Humphrey).
Bellacourt was subsequently expanded as the royal palace of Pleasaunce or 'Placentia' and it was here that Henry VIII was born in 1491.