I received several inquiries into the sword that is carved on the burial slab of Donnchadh Rua Mac Eáin. In Scotland, a sword on a burial slab symbolized a man of high rank. Pretty much that simple. The practice was in place very early in Scotland, certainly by the 1200 AD. Donnchadh Mór we know was a bailiff for the third Earl of Argyll, Coilin Caimbeul. Bailiff in late medieval Scotland was a very important position. A bailiff was the sheriff of a district and also was responsible for judicial proceedings. We know that Donnchadh Rua even travelled to Edinburgh on the Earl's business. His position as Bailiff alone elevated Donnchadh Rua to high status, but he was also a landed lord, head of the House of Dunemuck, which is in southern Kilmichael Glassary parish, very close to the village of Kilmichael Glassary, where is burial slab is located. While he served the Earl of Argyll, his clan affiliation was with Clann Mhic Lachlainn and he actually held his lands by grant of their Taoiseach (chief).
Donnchadh Rua Mac Eáin, to our knowledge, is the first of our family that used the surname Mac Eáin. We know this because he is recorded with that surname in multiple primary sources from the late 1400s into the early 1500s. His father was Ailean Mac Eáin Riabhach. Normally, in traditional Gaelic patronymics he would have been surname Donnchadh Rua Mac Ailean Mhic Eáin Riabhach, but in every case, even his burial slab, he was known by Mac Eáin, anglicised as McCain.