Probably a Leicester man, Clerk was made free of the borough in 1362, being excused the normal entry fine.4Leicester Bor. Recs. ii. 132. By 1377 he was duchy of Lancaster receiver and bailiff of the honour of Leicester, and thereafter remained in the service of John of Gaunt or his son until at least 1391.
Though he owned property in London and Northamptonshire, Clerk probably resided for most of his life in Leicester, where he rented a mercer’s shop from the commonalty.5CCR, 1377-81, p. 61; 1392-6, pp. 200, 217; Leicester Bor. Recs. ii. 156, 165. In 1389 he was chosen as warden of the guild of the Assumption in All Saints’ church, and in the same year was one of three burgesses who attended the trial, before Archbishop Courtenay at St. Mary’s abbey, of seven local lollards.6Trans. Leics. Arch. Soc. xiv. 167; Concilia Magna Brittaniae ed. Wilkins, iii. 209. Mayor for two consecutive terms in 1390-2, Clerk represented the borough in Parliament in 1391 while in office. Peter Clerk alias Barwell, another duchy servant; was perhaps a relation.