Maid Marian was the name of a character in Human mythology. Living in 12th century England, she had a romantic relationship with Robin Hood, the leader of the Merry Men. She was captured by Sir Guy of Gisbourne who wanted her as his wife. When she refused him, she was found guilty of outlawry and treason and sentenced to death. Robin Hood then saved her from execution. This rescue from Nottingham Castle was one of the most famous things Robin Hood was known for.
In 2367, the entity known as Q transported the senior officers of the USS Enterprise-D into a recreation of Sherwood Forest and the story of Robin Hood in an attempt to teach Captain Picard a lesson about love. During the reenactment, each of the officers played the part of one of the Merry Men. The role of Maid Marian was played by Vash, who was aboard the Enterprise at the time for the annual Federation Archaeology Council symposium. (TNG: "Qpid")