Armies Held Apart
Archived: 26 September 2026
In 1113, Ireland was dominated by rivalry between Muirchertach Ua Briain of Munster and Domnall Ua Lochlainn of Ailech, whose coalitions threatened conflict. Domnall expelled Donnchad Ua hEochada and partitioned Ulaid, while Muirchertach mobilised Leinster and Connacht forces in response. On two occasions Cellach, successor of Patrick at Armagh, prevented battle, ultimately securing a year’s truce with the sacred Bachall Ísu. The events demonstrated Armagh’s ecclesiastical authority amid church reform. Local dynastic killings, cattle mortality, pilgrimage deaths on Croagh Patrick, and shrine-work at Clonmacnoise also reveal instability, devotion, economic vulnerability, and patronage. Neither overking prevailed before Muirchertach’s illness in 1114.