Brian Oge O'Rourke (died 28 January 1604) was the penultimate king of West Breifne

Kingdom of Breifne

The Kingdom of Breifne or Bréifne was the traditional territory for an early Irish tribal group known as the Uí Briúin Bréifne...

, from 1591 until his death in 1604. He succeeded his father, Brian O'Rourke

Brian O'Rourke

Lord Brian na Múrtha Ó Ruairc , hereditary lord of West Bréifne in Ireland during the later stages of the Tudor conquest of that country, was proclaimed by the English to be a rebel and became the first man extradited within Britain for crimes alleged to have been committed in Ireland.-Early life:Ó...

, when news of the latter's execution in London reached Ireland. In 1599, his forces fought alongside those of "Red" Hugh O'Donnell

Hugh Roe O'Donnell

Aodh Rua Ó Dónaill, anglicised as either Hugh Roe O'Donnell or Red Hugh O'Donnell , was An Ó Domhnaill and Rí of Tir Chonaill . He led the Irish forces against the English conquest of Ireland from 1593 and helped to lead the Nine Years' War from 1595 to 1603...

 at the Battle of Curlew Pass

Battle of Curlew Pass

The Battle of Curlew Pass was fought on the 15th of August 1599, during the campaign of the Earl of Essex in the Nine Years' War, between an English force under Sir Conyers Clifford and a rebel Irish force led by Hugh Roe O'Donnell. The English were ambushed and routed while marching through a pass...

, during the Nine Years' War

Nine Years' War (Ireland)

The Nine Years' War or Tyrone's Rebellion took place in Ireland from 1594 to 1603. It was fought between the forces of Gaelic Irish chieftains Hugh O'Neill of Tír Eoghain, Hugh Roe O'Donnell of Tír Chonaill and their allies, against English rule in Ireland. The war was fought in all parts of the...

. His forces, along with those of Hugh O'Neill, 2nd Earl of Tyrone, were still suffiently menacing to Queen Elizabeth I of England

Elizabeth I of England

Elizabeth I was queen regnant of England and Ireland from 17 November 1558 until her death. Sometimes called The Virgin Queen, Gloriana, or Good Queen Bess, Elizabeth was the fifth and last monarch of the Tudor dynasty...

 that she was persuaded to agree to a peace in Ireland - the Treaty of Mellifont

Treaty of Mellifont

The Treaty of Mellifont , also known as the Articles of Mellifont was signed in 1603 ending the Nine Years' War which took place in the Kingdom of Ireland from 1594 to 1603.- The end of the war :...

.

In accordance with his wishes, he was buried in the cloister of the Ross Errilly Friary

Ross Errilly Friary

The Ross Errilly Friary is a medieval Franciscan friary located about a mile to the northwest of Headford, County Galway, Ireland. It is a National Monument of Ireland and among the best-preserved medieval monastic sites in the country...

. He was succeeded by his brother, Tadhg mac Briain na Murtha.