There was a rich farmer’s daughter, near Limerick she did dwell.
She was handsome, fair and hearty, her parents loved her well.
She was admired by lords and squires, but their hopes were all in vain;
For there was but one, a farmer’s son, whose heart he [she] could claim.

For some time young William courted her and arranged a wedding day.
Her parents all gave their consent, but her brothers they said, ‘Nay!
There is a lord who has pledged his word, and him you cannot deny.
For we will slay, and we will betray your constant farmer’s son.’

Well the fair being held not far from town, the brothers they went there.
And they asked young Willie’s company, with them to spend the day.
The day being spent, the night came on, they said his life was run,
And ‘twas with a stick, the life did take, of her constant farmer’s son.

And as Mary on her pillow lay, she had a frightful dream,
She dreamt she saw her own true love, lying in a purling stream.
She then arose, put on her clothes, to seek her love she ran,
When cold and low, she did behold her constant farmer’s son.

The tears ran down her rosy cheeks, all mingling with his gore;
And to relieve her troubled mind, she straightaway home did go.
Saying, ‘Mother dear you soon will hear of a dreadful deed that’s done,
For in yonder vale, lies cold and pale, my constant farmer’s son.’

Now these villains soon, they owned their guilt, and for this they both did die.
The doctors got their bodies all for to practice by.
But Mary’s thoughts both night and day on her true love they do run.
And in a madhouse cell, she now does dwell, for her constant farmer’s son.

Reference:
The Wanton Seed, Frank Purslow, EFDSS Publications 1968.
Jim Carroll

See also
Constant Farmer's Son sung by Tom Lenihan