Mac William Íochtar
Mac William Íochtar (Lower Mac William) was a term meaning both a territory and a title in Ireland. The territory covered much of the northern part of the province of Connacht. The Mac William Íochtar functioned as a regional king and received the White Rod. The title was a successor office to the Lord of Connacht which ended upon the murder of William Donn de Burgh, 3rd Earl of Ulster, in June 1333.
As a result of the Burke Civil War of the 1330s, the Lordship of Connacht was split between two opposing factions of the de Burgh family: the Burkes of Mac William Uachtar (or Clanricarde) in southern Connacht and the Mac William Íochtar Bourkes of northern Connacht. For over three hundred years, the two families dominated the politics of the province, frequently fighting each other for supreme rule of both the Anglo-Irish and Gaelic-Irish peoples.
List of Mac William Íochtar
- Edmond Albanach de Burgh, 1332-4 November 1375.
- Thomas mac Edmond Albanach de Burca, 1375-1402.
- Walter mac Thomas de Burca, 1402-7 September 1440.
- Edmund na Féasóige de Burca, 1440-1458.
- Tomás Óg de Burca, 1458-1460.
- Risdeárd de Burca, 1460-1469 (died 1473)
- Ricard Ó Cuairsge Bourke, 1469-1473.
- Theobald Bourke, 1479-5 March 1503.
- Ricard Bourke, 1503-7 July 1509.
- Edmond de Burca, 1509-23 February 1514.
- Meiler Bourke, 1514-28 April 1520.
- Edmond de Burca, 1520-29 September 1527.
- Seaán an Tearmainn Bourke, 1527-?
- Theobald mac Uilleag Bourke, ?-1537.
- David de Burca, 1537-?
- Ricard mac Seaán an Tearmainn Bourke, ?-1571.
- Seaán mac Oliver Bourke, 1571-1580.
- Risdeárd an Iarainn Bourke, 1580-1582.
- Risdeárd Bourke, 1582-1586.
- William An tAb Caoch Bourke, 1586-1593.
- Tiobóid mac Walter Ciotach Bourke, 1593-c.1606.
- Risdeárd mac Deamhain an Chorráin Bourke, 1600-?
- Tiobóid na Long Bourke, 1567-18 June 1629.
- Miles Bourke, 2nd Viscount Mayo, 1629-1649.
- Earl of Mayo
- Viscount Mayo
- Marquess of Sligo
- Baron Connemara
- Carter-Campbell of Possil
- Earl of Clanricarde
- Lower Mac William and Viscounts of Mayo, 1332-1649, in A New History of Ireland IX, pp. 235–36, Oxford, 1984 (reprinted 2002).