The office was received hereditarily, but a new king required the consent of the people before assuming the throne. All sons of the king had the right to claim the throne, which often led to co-rulership (diarchy) where two brothers were elected kings at the same time. This evolved into the territories being considered the hereditary property of the kings, patrimonies, a system which fueled feudal wars, because the kings could claim ownership of lands beyond their de facto rule.