Ranald, whose principal seat was Castle Tioram in Loch Moidart, became the progenitor of the MacDONALDS of CLANRANALD, descended from his eldest son, Allan and the MacDONELLS of GLENGARRY, descended from his second son, Donald.
By his second wife, John had several sons. The eldest son, Donald, succeeded him as Lord of the Isles and fought the Battle of Harlaw, in Aberdeenshire, against the Government forces, under the Earl of Mar, in 1411; the second son, Iain Mòr Tanaistear, i.e. Big John the Heir, founded the CLAN IAIN MHOIR or MacDONALDS of DUNYVAIG, with lands in Isla, Kintyre and Antrim, sometimes known as the CLAN DONALD SOUTH to distinguish them from the MacDonalds of Sleat who were also known as the CLAN DONALD NORTH; the third surviving son, Alexander was granted the Lordship of Lochaber and it is from his natural son, Alasdair Carrach (Mangy) that the MacDONALDS or MacDONELLS of KEPPOCH, also known as the CLAN RANALD of LOCHABER, from Ranald Mór, the 7th Chief of that branch, descend.
Donald of Harlaw was succeeded as Lord of the Isles and High Chief of Clan Donald by his eldest son, Alexander, who inherited, through his mother, the Earldom of Ross - the reason why the Battle of Harlaw was fought by his father. Alexander had three sons. The eldest, John, by his wife Elizabeth Seton, succeeded him as Lord of the Isles and Earl of' Ross.
The second, Celestine, by a daughter of MacPhee of Glen Spean, became the progenitor of the MacDONALD of LOCHALSH, the larger part of whose lands passed, in the sixteenth century to Glengarry.
The third son, Uisdean, or Hugh, by a daughter of Gilpatrick, grandson of the Green Abbot of Applecross, became the progenitor of the CLAN UISDEAN or MacDONALDS of SLEAT.
The weakness of John, the fourth Lord of the Isles and his reliance on the advice of persons out with his own family on how to govern his vast: territories, which led to his defeat by his son Angus Òg, in the naval engagement off MuIl, known as the Battle of Bloody Bay, his intrigues with the English Government and his failure to match the duplicity of the Campbells, resulted in his final forfeiture by the Crown in 1493.
