The Fens monks are a group of conspirators under the rule of Prince John
, recruited from thieves and other criminals.
At one point Robin Hood found one of the monks in Sherwood while trying to kidnap Maid Marian and they fought with a quarterstaff.
Sometime later he penetrated the Fens monastery to recover the hand scroll for Maid Marian. While in the monastery, he also saved Fulk the jester from being tortured.