Hieronymus Lex is an imperial gaurd and watch captain of the Imperial City, later re-assigned to gaurd captain of Anvil. His nemesis is the Gray Fox and his life long goal is to put him behind bars. Ironicly Lex is never able to catch the Gray Fox because of his re-assignment to Anvil, where the Gray Fox is the count.
Lex has wanted posters for the Gray Fox up all over the Imperial City. He had asked Adamus Phillida to put a bounty on the Gray Fox's head but Adamus like most people believe the Gray Fox and the Thieves Guild to be purley myth and thus refused.