His birth date range is estimated on the assumption that he was the father of his successor, Earl Gillbride/Gibbon/Gilbert (see under the Earls of Caithness, below)."Domino Magnus filio Comitisdomino Anegus filio Comitis" witnessed the charter, dated to [1226/39], which confirmed the donation of "terra de Othirlonyterram de Kenny" to Aberbrothoc by "Valterum filium Turpini".
During the 10th century the province of Argyll was added, and in the 11th century Buchan separated from Mar, while Caithness was conquered by the Norwegians.
The earldom of Dunbar was a further creation of the early 11th century, although it was only called as such from the early 13th century.
Six of these local rulers are for the first time called "comes" in the foundation charter of the monastery of Scone dated [1114/15].
According to Skene, the relationship between these rulers and their provinces was not purely territorial but connected with the tribes which occupied the land.
After the introduction of the feudal system into Scotland in the 12th century, the earldoms were descendible to heirs general was one of the seven original provinces of Scotland, covering about the same territory as the modern Scottish county of Forfar.
Its ruler was one of the six Mormaers who were described as "comes" in the [1114/15] charter of Scone. The 10th century Pictish Chronicle Cronica de Origine Antiquorum Pictorum records the death of "Dubucan filius Indrechtaig mormair Oengusa, Adalstan filius Advar rig Saxan, et Eochaid filius Alpini" .
The chapters on the Scottish earls and lords which are set out below are arranged in approximately chronological order of creation of the titles.
The first group of seven earldoms, Angus, Atholl, Caithness, Fife, Mar, Moray and Strathearn, corresponds to the seven provinces into which Scotland north of the Firths of Forth and Clyde was divided in the 9th century, reputedly ruled by seven brothers.
It was presumably after , the date of a charter under which Alexander II King of Scotland donated revenue from mills in Invernarn to the bishopric of Moray which was witnessed by "M comite de Anegus et Katania".