A charter dated 1351 which confirmed the donation of "terram de Kenny" to Aberbrothoc by "Walterum filium Turpini" quotes a document witnessed by "Domino Magno filio Comitis Domino Anegus filio Comitis".He was apparently installed as Earl of (part) Caithness.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.
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.
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".
Gillbride was the first individual to be styled (in 1135) Earl of Angus and members of his family succeeded him in the title until the mid-13th century. The Pictish Chronicle names Conchar Mormaer of Angus as father of Fynebole Lady of Fettercairn, who murdered Kenneth II King of Scotland in 995 in revenge for the slaughter of her only son oat Dunsinane. The Chronicle of the Scots and Picts dated 1177 records that "Kynnath mac Malcolm" reigned for 24 years and 2 months, was killed "a suis hominibus in Fetherkern" through the treachery of "Finuele filie filie Cunthar comitis de Anguss" whose only son had been killed by the king.