Morggán of Mar, is the first Mormaer or Earl of Mar to appear in history as "more than a characterless name in a witness-list.". His father was Gille Chlerig. He is often known as Morgrund or Morgan.
It is possible that Morggán participated in the so-called Revolt of the Earls, a protest by some of the native Scottish nobility at King Máel Coluim IV's trip to France as a vassal of King Henry II of England.
It is also possible that he became estranged from the French-speaking king William I, as Morggán's name appears in no royal acts of the latter king's reign.
He married Agnes, a patroness of churches. Agnes was probably related to the de Warenne family - the family who married Ada de Warenne to Henry of Scotland and mother of Kings Malcolm IV and William the Lion. Morggán and Agnes had at least one son, Donnchad, who eventually succeeded to become a Mormaer of Mar. Morggán had another two sons, Máel Coluim and James, but they may have been illegitimate - i.e. the product of an uncanonical marriage acceptable in the Celtic system, but not in the Franco-Roman system then gaining favour in Scotland.
His daughter Alesta of Mar was married to Alan Fitzwalter, 2nd High Steward of Scotland who was possibly mother to Walter Stewart, 3rd High Steward of Scotland.
He appears in royal charters dated as early as 1147. He is attested in the documents for the last time in 1178, and was dead by 1183.