 Tweed mentions that Tavis' father, Cailien (Colin) Maol Maith, died at the siege of Dunstaffnage in 1110.A possible time frame for the birth of Tavis would then be somewhere around 1100–1111, based in part upon the texts of the old MacEwen sheannachies.Alastair Campbell of Airds says, "It seems probable that later compilers of the official genealogy, "Ane Accompt" ("of the Genealogie of the Campbells"), did not know of Sir Thomas "Cambel" and were anxious to insert the MacTavishes into the account somehow."