Defeat at Ard Monann
Archived: 26 September 2026
Abstract
In 1075, Tairdelbach Ua Briain, king of Munster, led a broad coalition northwards seeking hostages from Airgíalla and Ulaid, but his heir Muirchertach was defeated at Ard Monann near Ardee, exposing limits to Ua Briain power. Nevertheless, Tairdelbach secured Dublin after Gofraid's exile and Domnall's brief reign, installing Muirchertach in the commercially and strategically vital Hiberno-Norse city. Annals also record deaths among northern rulers and churchmen, fires at Louth and Clonard, and Dublin's ecclesiastical links with Canterbury. Rural farming, woodland resources and urban craft and trade underpinned political and religious institutions; an abundant mast crop highlighted the economy sustaining them.