Cellach Cualann

Cellach Cualann mac Gerthidi (died 715) was the last Uí Máil king of Leinster. Cellach's byname is derived from the land of Cualu which lay around Glendalough.

The name Uí Máil may mean "grandsons of the princes". This, along with their ownership of certain objects symbolic of the kingship of Leinster, has suggested that they may once have been considered the rightful rulers of Leinster, at least by themselves. Alternatively, Uí Máil may have derived their name from the Glen of Imaal, in the west of modern County Wicklow, which lay in the centre of their historic lands.

Cellach's father was not king of Leinster, but his second cousin Fiannamail mac Máele Tuile (died 680) was. Cellach succeeded his cousin as king of Uí Máil when Fiannamail was murdered by a servant named Fochsechán, probably on the orders of Fínsnechta Fledach. The kingship of Leinster passed to the Uí Dúnlainge in the person of Bran Mut mac Conaill who died in 693, to be followed as king by Cellach.

Immediately after the death of Bran Mut a battle between the Leinstermen and their western neighbours the kingdom of Osraige is recorded, but Cellach is not associated with this. Cellach was one of the guarantors of the Cáin Adomnáin (Law of Adomnán) in 697 promulgated at the Synod of Birr.

In 704 he warred with his northern neighbours, the Uí Néill of Clann Cholmáin, led by Bodbchath mac Diarmata Déin, and of Síl nÁedo Sláine, led by Fogartach mac Néill. The Battle of Claenath, fought near Clane in modern County Kildare, was a victory for Cellach, with Bodbchath killed and Fogartach fled. In 707 the Uí Néill High King of Ireland Congal Cennmagair campaigned in Leinster and obtained Cellach's submission to his authority.

...
Wikipedia