Not about the song as such, but a story connected tangentially:

middle of the nineteenth century, Donegal, farmer was promised dowry of £50 along with the intended wife. Marriage took place; dowry wasn't paid (echoes of "Quiet Man" movie). Farmer said nothing. About ten years, and six children later, the wife died (perhaps in childbirth). Farmer carted the remains to the churchyard nearest to her family home, and - according to the story - "threw her in owre the graveyard wall, and then went home whistling 'The Girl I left behind Me'".