Donald Grumach MacDonald of Sleat was the son of Donald Gallach MacDonald of Sleat.
Donald's nickname, Grumach, means ill favored or grim or gloomy, It indicates that he had a scowling or frowning countenance.
Different sources name his wife as Catherine or Margaret MacDonald,daughter of Allistair MacDonald of Clanranald and Moidart.
Donald Grumach was murdered by his brother, known as Black Archibald or Archibald the Clerk. Archibald invited him to dinner to see his new gallery and during dinner stabbed him in the back. Archibald had previously killed his other brother by strangling him. I have seen the word clerk attached to other mens names and it meant they were in some way trained for service to the church. If this is how Archibald received his education, he certainly did not turn out to be a saint.
The Highlands and Islands of Scotland and a few other places say that the fortress of Eilean Donan was besieged by Donald Grumach in 1539, but if Scottish Clans and Their Tartans is correct, then it was his son Donald Gorm who beseiged it. That is exactly what George Hill records in his book on the MacDonnells of Antrim. So it seems that it was Donald Gorm who besieged the castle of Eilean Donan.
Scottish Clans and Their Tartans says that Donald Grumach died in 1534, and was succeeded by his elder son, Donald Gorm, who claimed the lordship of the Isles and was killed in 1539 in pursuit of his claim. He in turn was succeeded by his son Donald, known as Domhnull Gorm Sasunnach, because he had spent his minority in England. He died in 1585, and was succeeded by Donald Gorm Mor, his son. Donald Gorm Mor died without issue and was succeeded by his nephew, Donald MacDonald of Sleat.
An historical account of the Macdonnells of Antrim
By George Hill
Chambers's English dictionary: pronouncing, explanatory, and etymological ... - Page 909
by James Donald - Foreign Language Study - 1872
History of Skye: a record of the families, the social conditions, and the ... - Page 49
by Alexander Nicolson - Hebrides (Scotland) - 1930
The Highlands & islands of Scotland - Page 73
by Allan Campbell McLean - History - 1976 -
The Scottish Clans and Their Tartans
by Anonymous, Kessinger Publishing Company - History - 2005