I have ben thinking about the origins of this beautiful song, which I would like to throw in as a theory, based on the real history of the Ireland.

Queen Elizabeth (the first) sent her commander Henry Bagenal as Marshall of Ireland to sort out the Irish rebel Hugh O'Neill, 2nd Lord of Tyrone, who was causing the Tudor monarch a great deal of trouble at the time.

The English had built an outpost on the banks of the river Blackwater very near to O'Neill's power base. Seeing this as a threat O'Neill laid siege to the outpost. Bagenal was obliged to send 4000 men to both relieve & resupply the outpost. Unfortunately for the English, O'Neill got word of their approach & arranged an ambush, killing nearly all of the English troops & mortally wounding their commander Bagenal. This become the known later as the battle of the Yellow ford.

Could this song be a thinly vailed reference to Irish History?

Could it be that the girl in the song who is so badly deceived is Queen Elizabeth the first, the Irish lad who deceives her O'Neill & the garden the girl is told to go back to be her father's (Henry the Eigth) Hampton court palace?