Strathearn was also the name of an ancient province of the Kingdom of Alba,[2] under the authority of a mormaer and then an Earl.
The earliest attested mormaer of Strathearn is Mael Ísu I, who is recorded fighting alongside David I at the Battle of the Standard in 1138.
[3] Unlike some provinces where the holder of the office of mormaer rotated between kin-groups, the mormaership of Strathearn was dominated by a single family, with a Mael Ísu in every generation until the death of Mael Ísu V in the mid 14th century.
[3] In 904, during the reign of Constantine II of Scotland, sons of Bárid mac Ímair sent a Danish army to attack Strathearn, and were ultimately defeated, the Kingdom of Scotland wasn't attacked by Vikings for the next 50 years.
Strathearn became a stewartry under the authority of the Earls of Perth and part of Perthshire for administrative purposes, until the abolition of heritable jurisdictions in 1748.