According to Brewer's Dictionary of Phrase and Fable "Greensleeves" was a popular ballad in the time of Queen Elizabeth I. It is apparently mentioned in Shakespeare's "The Merry Wives of Windsor." During the English Civil War it was used as a tune for political ballads and is mentioned by Samuel Pepys under the title of The Blacksmith. I heard many years ago and I don't know how true it is that prostitutes in Tudor times were required by law to wear green-sleeves.