The village name is Anglo Saxon in origin, and means 'green hill'. In the Domesday Book of 1086 the village was recorded as Grenesberga.
Anciently the manor at Granborough was owned by the abbey at St Albans, though in the dissolution of the monasteries in 1547 ownership passed automatically to the Crown.
The ancient parish church, dedicated to St John the Baptist, was demolished during the English Civil War, though was rebuilt shortly after the Restoration of the Monarchy in 1685.
The village is still one of the possessions of the Crown.