The O’Donnell dynasty (Irish: Ó Dónaill or Ó Domhnaill, Ó Doṁnaill or Ua Domaill; meaning “descendant of Dónal”) were the dominant Irish clan of the kingdom of Tyrconnell in Ulster in the north of medieval and early modern Ireland.
Tyrconnell (also known as Sir Chonaill) was an ancient Gaelic kingdom located in the northwest of Ireland, primarily the modern donegal as well as parts of Sligo, Leitrim, Tyrone and Londonderry. The kingdom was named after Conall Gulban, a son of Niall of the Nine hostages and was ruled for centuries by the O’Donnell dynasty.
Like the family of O’Neill, that of O’Donnell of Tyrconnell was of the Uí Néill, i.e. descended from Niall of the Nine Hostages, High King of Ireland at the beginning of the 5th century; the O’Neill, or Cenél nEógain, tracing their pedigree to Eógan mac Néill, and the O’Donnells, or Cenél Conaill, to Conall Gulban, both sons of Niall. Conall was baptised by St. Patrick.
The O’Donnells were often rivals and sometimes allies of the neighbouring O’Neill clan of Tyrone.
During the Nine Years’ War of 1593-1603, the O’Donnells of Tyrconnell played a leading part, led by the famous Prince Red Hugh O’Donnell. Under his leadership, and that of his ally Hugh O’Neill, they advanced to Kinsale and laid siege to the English forces in anticipation of a Spanish invasion.
After their defeat at Kinsale in 1601 and the subsequent Flight of the Earls in 1607, the O’Donnell chiefs lost their traditional power.
O’Donnell in Exile
Rory O’Donnell, 1st Earl of Tyrconnell (1575–1608)
Died in Rome only a year after arrival.
His brother Cathbarr O’Donnell also died in exile.
Their heirs, like the O’Neills, became military leaders in continental Europe.
Red Hugh O’Donnell (1572–1602) — already in exile before the Flight, having gone to Spain seeking aid.
Died mysteriously in Valladolid, Spain.
Spanish chronicles preserve the O’Donnell presence at court.
O’Donnell Crest
Motto
“In hoc signo vinces” – Latin for “In this sign you will conquer.”
This refers to the Christian cross and reflects the clan’s deep Catholic faith and warrior tradition.
Shield: Typically features a red cross on a gold (or silver) background, often quartered with other heraldic symbols such as stags or lions.
Crest (above the shield): A red hand holding a cross, symbolizing both faith and defiance.
Supporters: In some versions, stags or other animals, representing nobility and connection to the land.
Symbolism
Red Cross: Bravery and sacrifice.
Stags: Peace, harmony with nature, and sovereignty.
Hand with Cross: Leadership guided by faith, and the clan’s willingness to fight for independence and belief.
