Robin Hood and the Monk is Child ballad 119, and among the oldest existing ballads of Robin Hood, existing in manuscript from about 1450.
It may have been originally recited rather than sung; it refers to itself as a "talking" in its last verse:
However, this is by no means certain, since the word "talking" could also mean a written discourse or information in Middle English.
There are notable parallels between this ballad and that of Adam Bell, Clym of the Cloughe and Wyllyam of Cloudeslee, but whether either legend was the source for the other can not be established.
Little John talks of the May morning, but Robin Hood is still unhappy, because he cannot go to Mass or matins. He decides to go to a service in Nottingham, inspired by his devotion to the Virgin Mary. "Moche, the mylner sun" (Much the Miller's Son) advises him to take at least twelve men; he refuses and goes with only Little John.
On the way, he makes a bet with Little John, loses, and refuses to pay. Little John leaves him.
Robin goes to St. Mary's in Nottingham and prays. A monk who he had robbed sees him and tells the sheriff, who goes with many men and fights with him.
The text breaks off at this point; neither Robin's capture nor the news reaching his men are included, but the story takes up with the men's shock, and Little John's being the only one to keep his wits about him. He declares they must rescue him. They catch the monk riding with a little page; Little John kills the monk for his treachery, and Much kills the page so that he could not tell who they were.
Little John and Much go to the (unnamed) king with the monk's letters and tell him the monk died on the way. The king gives them gifts and directions to bring Robin Hood to him. Little John brings the letters to the sheriff and tells him that the monk did not come because the king had made him an abbot. They get into the prison, kill the jailor, and escape with Robin. The sheriff does not dare face the king. Robin says that Little John has done him a good turn in return for the ill one he played, and offered to be his man; Little John still wants him to remain his master.