Glen Fruin (Glenn a Bhroin or Valley of Sorrow), near Loch Lomond, was the site of a desperate engagement between the MacGregors and the Colquhouns, in 1603.   It is said that two MacGregors were passing through Colquhoun territory, where they were denied shelter and refreshment.  They fed themselves on a sheep they took from an adjoining field, and then offered to pay for it.  Instead of accepting any payment the Colquhouns condemned and hung the two MacGregors.

This incident escalated into a feud eventually resulting in the battle at Glen Fruin where, although outnumbered, the MacGregors ambushed, routed and slaughtered the Colquhouns, Buchanans, Grahams and Lennox townspeople who had been on their way to MacGregor territory with the King's consent to put fire and sword to the MacGregors and their property.

This rout resulted in the severe enactment's against the MacGregors where their name was proscribed.

The poem was written by Forbes MacGregor.  The piobaireachd, also titled The Rout of Glen Fruin, is said to have been published in 1821.  A piobaireachd is a piece, played on the bagpipes, which is a series of stylized variations on a theme..