The First Appearance of "Macrae" as a Surname
In those times [tenth century] there were no family or hereditary surnames in this country. Family surnames appear in England about the twelfth century, but it was not until much later that they became common in the Highlands of Scotland. For instance, the surname Mackenzie, which is a comparitively old one, arose in the early part of the fourteenth century. The use of Macrae as a surname is probably of an earlier date than the surname Mackenzie, and that it grew in the first instance out of a personal name is evident from the fact that in Gaelic the Macraes are always spoken of as "Clann Mhicrath," that is the "descendents of Macrath."
So far as at present known, the name Macrae is first mentioned as a surname in the year 1386, in an agreement made, at Inverness, between the Bishop of Moray and Alexander Stewart, Earl of Buchan, better known as the Wolf of Badenoch, with regard to some land in Rothiemurchus, in Inverness-shire, which was formerly occupied by a certain Cristinus M'Crath (Christopher Mcrae), who was then dead.1
Next: Traditional Origin of the Clan Macrae
1. Registrum Episcopatus Moraviensis (Bannatyne Club), page 196.