Deaglán mac Conán Ceiltiach Declan mac Conan de Celtia Declan I
Portrait of Deaglán mac Conán Ceiltiach Declan mac Conan de Celtia
High King of the Celts High King of Britannia High King of Ireland
1287 – 1342
None (position established)
1256 Tara, Ireland
Guinevere nic Coinnich
Arthur Brendan Gwendolen
Declan I of Celtia (Celtic: Deaglán I de Celtia), full name Declan mac Conan de Celtia (Celtic: Deaglán mac Conán Ceiltiach), was a Celtic warrior who led a revolt against the Norse Empire, liberating it from the Norse rule and was crowned High King of the Celts.
Declan was succeed by his eldest grandson, Arthur, who seized the throne from his sister Morgana, who had been the king's designated successor.