The famous Robertson device of three wolf heads appears on their seals as early as 1438. In those days, their homeland of Atholl was still the haunt of wolves, but the reason for choosing this device has been lost. If it could be shown that the wolf was an heraldic beast of Clan Donnachaidh’s ancestors, the Earls of Atholl, one might conjecture that it was a pun on the name of their forefather Madach, first Earl of Atholl, since Madach resembles madadh-allaidh, Gaelic for Wolf.
When a leader died, his heir “succeeded to his coat.” The coat of arms of Struan Robertson was three silver wolf heads on a red background, and each successive Chief of Clan Donnachaidh has inherited the coat of arms, just as The Queen or King of England inherits the Royal Arms from their successor.
By Act of Parliament, no one may use a coat of arms unless it is registered in the books of the Lord Lyon, who has a duty to decide to whom it rightfully belongs in any generation and who is therefore called upon to judge disputes of chiefship. Since no two men can use the same coat of arms, other sons have to add to their arms some mark of difference to that of the head of their house, so they can be told apart. These “differences” are selected for them by the Lord Lyon, who is expert in such matters, and are carefully recorded in the books of his Court.
Thus in 1779, Robertson of Lude asked Lyon to record his arms and was allowed the three silver wolf heads on red, with a golden hand holding a cross added for difference between them. This was especially appropriate, as a hand holding a cross is an emblem of Clan Donald, an heiress of which the Robertsons may have inherited Lude.
So strict is the rule about “one man, one coat,” that during his father’s lifetime even the heir has to wear a “label” or tournament collar over his father’s coat, so that he won’t be confused with his father.