Clan Gregor on Wikipedia
Clan Gregor, Clan McGregor, Clan MacGregor or Clan M'Gregor is a
Highland Scottish clan. It is the most senior clan of Siol Alpin, translated as (Seed of Alpin) referring to King Kenneth I, descending from the ancient Kings of the Picts and Dál Riata. Outlawed for nearly two hundred years after a long power struggle with the Clan Campbell, the Clan Gregor claims descent from Constantin and wife and cousin Malvina, first son of Doungallas and wife Spontana (daughter of a High King of Ireland) and grandson of Giric, the third son of Alpín mac Echdach, the father of Kenneth MacAlpin, the first King of Scotland, a descent which is proclaimed in the motto, 'S Rioghal Mo Dhream, translated as Royal is my Race.