O'Donnell

The Ó Domhnaill kings of Tír Chonaill, the kingdom that occupied most of modern Donegal, were the second great northern dynasty after the O'Neills, and through the 15th and 16th centuries the most consistently independent of the Gaelic provincial powers. Their seat was at Donegal Castle on the bay, with secondary fortresses at Lifford on the Foyle and Doe Castle on Sheephaven Bay. The Cistercian abbey at Donegal town, founded by Hugh Ó Domhnaill in 1474, was one of the principal centres of Gaelic scholarship and chronicle-writing into the 17th century.

Aodh Ruadh Ó Domhnaill, Red Hugh O'Donnell (c.1572–1602), is the central figure. Kidnapped by Sir John Perrot's agents in 1587 at age fifteen and held in Dublin Castle for three and a half years, he escaped on Christmas night 1591 (see legend), made his way back to Donegal, was inaugurated as the Ó Domhnaill in 1592 at Kilmacrenan, and led the western half of the Nine Years' War in alliance with his brother-in-law Hugh O'Neill of Tyrone. He fought the central battle of Curlew Pass in August 1599 and the disastrous battle of Kinsale on Christmas Eve 1601. He travelled to the Spanish court at Valladolid early in 1602 to seek a second Spanish expedition; he died there, aged twenty-nine, in September 1602, possibly poisoned. He is buried at the Franciscan friary in Valladolid.

His brother Rory O'Donnell, 1st Earl of Tyrconnell (1575–1608), inherited the title and led the Tyrconnell party of the Flight of the Earls in September 1607 (see the O'Neill legend). Rory died in Rome the following year. The Plantation of Ulster, beginning 1610, settled Donegal with Lowland Scots; the Ó Domhnaill cadet branches dispersed across the diaspora and to the Continent, where the O'Donnells of Spain, Leopoldo O'Donnell y Joris, Duke of Tetuán, Prime Minister of Spain three times in the 1850s and 60s, preserved the family name into European public life.