Following Britain's defeat in the Norman Conquest of 1066, Domesday Book was commissioned by the victorious William the Conqueror in December 1085 to record and detail his new territory.
The Domesday Book was completed in August 1086 and records over 13,000 villages, hamlets and settlements throughout Britain.
While its original purpose was to help decide levels and amounts of taxation, it has proved an invaluable snapshot of Britain in the 11th Century.
There are no fewer than 5 places with the name Hatfield recorded in the Domesday Book but there is only one in Hertfordshire (The actual name Hetfelle meant pasture or open land. Like many other places, there are many variations of its spelling – in the early days when only a few people could read or write, and there were changes in language, it took time for spellings to become standardised).
Hatfield's entry shows a small settlement with two watermills and a population of 55. The mill at Mill Green, shown in the photo, is thought to occupy the site of one of the original Domesday Book mills.
Coincidentally, William the Conqueror may have brought along a man whose descendants played an important part in Hatfield's history in the 20th Century. In his autobiography, Sky Fever, Sir Geoffrey de Havilland reveals that a cousin who researched their family tree produced a genealogy which noted a 'De Havylland' as one of the Conqueror's officers or knights.
The original Domesday Book survives at the National Archives at Kew.