In 1315 he was made a King's Serjeant, and in 1320 replaced John Benstead as a junior justice for the Common Bench, being knighted in the same year.
He left in 1329 to serve on two Eyres in Nottinghamshire and Derbyshire, and returned in 1331.
He left again in 1333, although he returned the same year, serving until 1335, making him one of only two Chief Justices of the Common Pleas to be appointed and then leave on three separate occasions; the other, Sir John Stonor, was his replacement on two of those occasions.
William Herle was The Lord of the Manor of Braunstone and overlord of Sir Simon Pakeman of Kirby Muxloe.
Robert, who inherited titles, estates and possessions from his father, left the manor of Kirby to his sister's son, Sir Ralph Hastings when he died in 1364 being the last male of the ancestral line.