Adam was born before 1190. He was the son of John Cailly.
In 1215 the Pipe Rolls mention him as, in about 1206, accounting for £5 for licence to plead before King John touching the dowry of wife of Michael de Poinings and Michael's wife Margery who was Adam's mother by a previous marriage to Adam's father John de Cailly. The case was to determine inheritance from his father (ie a case of "admensuration") in relation to his mother's dower in Bradenham, Denver and Ryston, Norfolk. There was a similar plea between Adam and Margery in 1232, and Adam had a fine in 1239 of land in Bradenham, possibly in settlement of the claim.
In 1215 King John instructed Hervy Belet or Bolet "that he do not receive into the king's peace Hugh de Plaix, Michael de Poynings, William de Stuteville, William de Mortimer, Adam de Cayly, and Robert de Clere, until the king otherwise commands": Adam had evidently joined barons' rebellion against John.
In 1232 the manor of Syde in Gloucestershire was divided between Maud Giffard, Adam de Cayley and his wife Mabel. In 1243 Adam held all or part of the manor. 
In 1240 Letters Close of 14 August show Adam de Kaylli holding 4 knights' fees in Norfolk in the honour of the late Earl William of Warenne who died in 1240.
In 1242-3 he held 1 fee in Hilborough and 1 in Cranwick, Norfolk.
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