Cantrefi of Dunoding
One of the stronger cantrefs of the Kingdom of Gwynedd, Dunoding was originally meant to go to King Cunedda Wledig's son, Dunoda (for which the region was renamed in the early 450s), but Dunoda died in an Irish raid and rule of the cantref has instead fallen to a distant cousin, Padern ap Cadwaladr.
Like most of Wales in the 5th Century, the Cantrefi of Rhos utilizes Agnatic Elective Gavelkind as its succession law: The titles of the ruler are divided among his children and the primary heir, who is elected from among the members of the ruling dynasty. The law defaults to Primogeniture. You get no Prestige penalty for having unlanded sons and can have a 30% larger demesne. Destruction of titles unader any form of Gavelkind succession is not allowed. On succession in kingdoms and empires, new kingdoms might be created for younger sons if possible. Junior heirs always get the choice to declare independence without a war. Only males can inherit.