Ptolemy XII Auletes
Congal ruled Ireland for fifteen or sixteen years, at the end of which he was killed by Lugaid Luaigne's grandson Dui Dallta Dedad. The "Lebor Gabála Érenn" synchronises his reign with that of Ptolemy XII Auletes (80–51 BC) in Egypt. The chronology of Geoffrey Keating's "Foras Feasa ar Éirinn" dates his reign to 135–120 BC, that of the "Annals of the Four Masters" to 184–169 BC.