Alfwold (d. 990) younger brother of Ailwyn, the founder of Ramsey Abbey, granted Bythorn to the monks. Like Brington, Bythorn, after appearing in the Domesday Book in 1086 as a 'manor' assessed to the geld of 4 hides, became a dependant part of the manor of Old Weston, the descent of which it followed is below.
It is related that Alflida, the wife of Alfwold, held Bythorn in dower and granted it to the monks of Ramsey, with a request that they would receive Aednoth, the son of her daughter, as a monk.
William 1 confirmed Bythorn to Ramsey in 1077, and ordered that half a hide, of which Humphrey the larderer disseised them, should be restored, as it was appropriated for the provision of their victuals and clothing.
Later William de Wychentone sold his land in Bythorn to the Abbot of Ramsey, who before 1254, had added it to the manor of Bythorn. Between 1254 and 1267 the Abbey allocated to the custody of the shrine of St Ives 2s. annual rent from their manor of Weston, brought from Andrew de Bythorn.
The agrarian holdings of Ramsey Abbey in the Domesday Book in 1086 was 4 hides which was valued as £4 for their estate. (Ref 25)