Morggán of Mar, is the first Mormaer of Mar to appear in history as "more than a characterless name in a witness-list." His father was Gilla 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 Ada, a patroness of churches. Morggán and Ada had at least one son, Donnchad, who eventually succeeded to the Mormaerdom. 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 favor in Scotland.

His daughter Alesta of Mar was married to Alan Fitzwalter, 2nd High Steward of Scotland and was 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 certainly dead by 1183.