Ruadrí, Earl of Mar

Ruadrí of Mar is the first known Mormaer or Earl of Mar from the 12th century, although that the mormaerdom was much older. For instance, there was a Mormaer of Mar at the Battle of Clontarf, 1014.

He was a witness to a confirmation of lands to the newly established Abbey of the Holy Trinity at Dunfermline, by David I in 1128.

He is mentioned as Ruadrí mormar Marr in the Gaelic notes on the Book of Deer. This means his floruit dates a little after 1130.

...
Wikipedia