fineux was the son of william fyneux of swingfield, kent, his mother's name being monyngs. the family of fyneux or fineux (sometimes also written finiox or fineaux) was of great antiquity in kent. the judge is said by fuller, on the authority of one of his descendants, a certain thomas fyneux, to have begun the study of law at the age of twenty-eight, to have practised at the bar for twenty-eight years, and to have sat on the bench for the same period. as he died not earlier than 1526, he must, if fuller's statements are correct, have been born about 1441. he was a member of gray's inn and a reader there, though the dates of his admission, call, and reading are alike uncertain. he was appointed in 1474 one of the commissioners for administering the marsh lands lying between tenterden and lydd, and in 1476 seneschal of the manors of the prior and chapter of christ church, canterbury. this is probably the origin of david lloyd's statement that he 'was steward of 129 manors at once' (christ church letters, camden soc. p. 95). on 20 november 1485 he was called to the degree of serjeant-at-law, his motto for the occasion being "quisque suae fortunae faber". this is the earliest recorded instance of a motto being assumed by a serjeant on occasion of his call. in 1486 he was sworn of the council. on 18 may 1488 he was appointed steward of dover castle, on 10 may 1489 he received a commission of justice of assize for norfolk, and on 14 august following he was appointed king's serjeant. lloyd says that he opposed the subsidy of a tithe of rents and goods demanded for the expenses of the war in brittany. this must have been in 1488-9.