Lafracoth O'Brien Peerage person ID=335172 (1076–1119) Parents Muirchertach Ua Briain Dubheboblaigh of Ossory Children Alice de Montgomery Siblings Mahon O'Brien, Prince of Corkobaskin Bjaðmunjo Mýrjartaksdóttir Domnall Gerrlámhach Partners Arnulf de Montgomery