John was the younger brother of William Chevir (died 1446) who also had a successful, if somewhat turbulent, political and judicial career.
John and his brother were strong supporters of the Earl of Ormonde's faction, which was one of the two main parties in Irish politics in the 1430s and 1440s.
[7] The Parliament of 1463 passed an Act restoring to him the mill and watercourse at Esker,[8] which had originally been granted to him in 1450, on his appointment as Master.
[9] These were attached to the manor of Esker near Lucan, Dublin, a Crown property which was often leased to public servants for their lifetimes.
He left part of his estate to his successor in office, Philip Bermingham, who was probably a relation by marriage.