 Áed mac Ainmuirech died in battle near Baltinglass, modern County Wicklow, fighting against Brandub mac Echach, King of Leinster.It was to distinguish him from that Áed and from others that Áed mac Diarmato received his cognomen, "Áed of Slane", referring to the Hill of Slane, a prehistoric site near the Hill of Tara, which lay within his lands.Some sources omit Áed from the list of kings, including the earliest, that found in the "Baile Chuind Chétchathaig", a work of dynastic propaganda compiled in the reign of Áed's grandson Fínsnechta Fledach.