Fiach Mac Aodha O Broin (Feagh or Fiach McHugh O'Byrne) (1534-1597), Lord of Ranelagh and sometime leader of the Clann Ui Bhroin (O'Byrne clan), during the Elizabethan conquest of Ireland - The Battle of Glenmalure on 25th August 1580 during the Desmond Rebellions. An Irish Catholic force made up of the Gaelic clans from the Wicklow Mountains led by Fiach MacHugh O'Byrne and James Eustace, Viscount Baltinglas of the Pale, defeated an English army under Arthur Grey, 14th Baron Grey de Wilton, at the O'Byrnes' mountain stronghold of Glenmalure.