The notes expain the background:
In 1544, after John Muidart escaped from prison and took over again as Chief of the Clan Ranald, he compelled Ranald Gallda and his party to leave. A battle was fought and the MacDonalds withdrew. Thinking they were the victors, Gallda and Lovat, who joined with him along with other clans, retired, but the MacDonalds caught up with them later. The day was warm, and the eager combatants, as they often did, stripped off their tartans and fought in their shirts, from which it was called “The Battle of the Shirts.” Only 8 MacDonalds survived and 4 Frasers. Of the Frasers it was recorded that, “lt happenit, by the singular benefite of God, that they left ther wyffs with chyld when they went to the feight, by which means that familie was afterwards raised and restored.”