MacDonnells of Antrim

The MacDonnells of Antrim (Gaelic: Mac Domhnaill; Ulster-Scots: M'Donnals), also known as the MacDonnells of the Glens, are a branch of the primarily Scottish-based Clan Donald in Ireland. Initially part of Clan MacDonald of Dunnyveg (Clan Donald South), the MacDonnells of Antrim became their own branch in 1558 when Somhairle Buidhe MacDonnell obtained the lordship of the territory in Ireland from James MacDonald, 6th chief of the Clan MacDonald of Dunnyveg. The MacDonnells of Antrim were a sept of the powerful Clan Donald of the royal Clann Somhairle, (see Lords of the Isles), that the English crown had attempted to cultivate since the early 14th century in its efforts to influence the course of politics in Scotland. The MacDonnells established a growing presence in Ireland throughout the 15th and 16th centuries, and played a crucial role in the politics of 17th century Ireland. Today the surname is predominantly spelled McDonnell in Ireland and abroad. Many of the present day McDonnells have a common descent from Sorley Boy MacDonnell.

The MacDonnells of Antrim are descended from John Mor MacDonald, chief of the Clan MacDonald of Dunnyveg. John Mor MacDonald was the second son of Good John of Islay, Lord of the Isles, 6th chief of Clan Donald, through John of Islays second marriage to Princess Margaret Stewart, daughter of King Robert II of Scotland.

John Mor MacDonald married Margery Byset, daughter of the Mac Eoin Bissett, Lord of the Glens of Antrim. Although the MacDonnells would a century and a half later claim that her dowry included the lordship itself, this is false because the Mac Eoin Bissetts remained in possession of it into the early or mid 16th century. However following the death in battle, in support of his friends and kinsmen the O'Neills against the O'Donnells, of the last known Mac Eoin Bissett in 1522, the recently arrived MacDonnells appear to have started making their own gains in the region and eventually used the earlier marriage to claim they had rights to the Bissett lordship. The MacDonnells already possessed Dunnyvaig Castle on the Isle of Islay and lands in Kintyre, Scotland.

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