Domesday Book was commissioned by William the Conqueror (1066-1087) at Christmas 1085. It was designed to show who held every piece of land in the newly conquered Kingdom of England. It was known colloquially as the Domesday Book because it was seen as being as final as the Last Judgement and as difficult to conceal things from. The book does not cover the whole country - Cumberland, Durham, Northumberland, and Westmorland were omitted and London and Winchester likewise, along with some other towns. A separate book, called Little Domesday covered the counties of Essex, Norfolk and Suffolk and, despite its name, it is actually bigger and more detailed than the Great Domesday Book containing the other counties.

There were two manors in Silsoe in 1086. The larger was owned by Walter, brother of Sihere and was one of two manors he had in the county, the other being at Segenhoe, today's Ridgmont. His Silsoe manor comprised four and a half hides and was tenanted by a man named Hugh. There was a mill worth 26 shillings (a watermill since windmills were unknown in England before the last quarter of the 12th century) and woodland for a hundred pigs. There were six villagers, eight smallholders and four slaves. Leofnoth had held four hides of this manor in 1066. He had also held Segenhoe, making it clear that Walter had simply taken over Leofnoth's manors. Three freemen had also owned half a hide in the manor and they could sell it freely of Leofnoth's permission. This half hide was held by Hugh directly from the King "as his men state" rather than from Walter. The manor had been worth £11 in 1066, falling to 100 shillings (£5) by the time Walter acquired it, though this had risen to £8 by 1086. The reason for falls in value such as this in Bedfordshire may be to do with depredations by the Conqueror's armies as they travelled north to deal with rebellions.

Another two hides in Silsoe were owned by Nigel d'Aubigny and were tenanted, rather unusually by one of his concubines or lovers, who, sadly, is not named. She managed two villagers, three smallholders and a slave as well as woodland for fifty pigs. Her holding had been the possession of a thegn called Aelfric Small in 1066 and had been worth thirty shillings. Surprisingly this value was the same when d'Aubigny acquired it and in 1086.