King is a royal title given to a male monarch. A king is an absolute monarch if he holds unrestricted governmental power or exercise full sovereignty over a nation. Conversely, he is a constitutional monarch if his power is restrained by fixed laws. Kings are hereditary monarchs when they inherit power by birthright and elective monarchs when chosen to ascend the throne. In the context of prehistory, antiquity and contemporary indigenous peoples, the title may refer to tribal kingship. Germanic kingship is cognate with Indo-European traditions of tribal rulership (c.f.
https://en.wikipedia.org/wiki/King