The Marquis of Douglas, a young man, after being engaged for marriage

with the daughter of one Widow Jack, a taverner at Perth, was wedded at Aba House to Lady Barbara Erskine, daughter of the Earl of Mar.—Lam.

This was an unfortunate marriage for the lady. The marquis, a man of profligate conduct, was subsequently led by his factor, Lowrie of Blackwood (said to have been a rejected suitor of the lady), to suspect his marchioness of infidelity, and they were consequently separated, after she had born him one child. The sorrows of the Marchioness of Douglas were described in a popular ballad of the day, some verses of which constitute the favourite song of Waly, waly!

just a little background info, the woman in this song was not the deceiver as Peter Pears says but the victim.
I like the James Taylor version best of the three clips, but each to their own