Battle of Glenmama

The Battle of Glenn Máma or Glenmama (Irish: Cath Ghleann Máma, The Battle of "The Glen of the Gap") took place most probably near Lyons Hill in Ardclough, County Kildare, Ireland, in AD 999 between Windmill Hill and Blackchurch. It was the decisive and only engagement of the brief Leinster revolt of 999–1000 against the King of Munster, Brian Boru.

The Battle of Glenmama in AD 999 was fought between the forces of Máel Sechnaill II, High King of Ireland, and the Leinstermen led by Brian Boru's ally, Donnubháin of Leinster. Máel Sechnaill was defeated, which weakened his position and helped consolidate Brian Boru's influence in Ireland, contributing to the eventual unification of the country under his rule.