Co-ruler

A coregency or co-principality is the situation where a monarchical position (such as king, queen, emperor or empress), normally held by only a single person, is held by two or more. It is to be distinguished from diarchies or duumvirates such as ancient Sparta and Rome where monarchal power is formally divided between two rulers.

Historical examples of this include the coregency of Frederick I of Austria and Louis the Bavarian over the Kingdom of Germany. Jure uxoris Kings in Kingdoms such as Spain and Portugal can also be found (Ferdinand V and Isabella I of Castile, Philip I and Joanna of Castile, Peter III and Maria I of Portugal, etc.). In Navarre, the husbands of queens regnant were styled as co-rulers.

Another example is in Ancient Egypt, mainly in the Middle Kingdom, where the Pharaoh occasionally appointed his successor (often one of his sons) as coregent, or joint king, to ensure a smooth succession. The Pharaoh also did this when he was elderly or unable to rule his country on his own (such as the case of Thutmose III and Amenhotep II or Amenemhat I and Senusret I). The existence of the practice makes establishing firm dates in Egyptian chronology more of a challenge, as the lengths of coregencies are often uncertain and complicate the use of accepted regnal lengths to establish dates. Some of the Queens of Egypt rose to a status of equal to the God-Kings, becoming co-rulers and / or at least as important in religious affairs, and were even portrayed with the same size as their male consort and even with the same size as the other Gods of Egypt. Such were the cases of Hatshepsut, Nefertiti, Nefertari and the Nubian Egyptian Queens. In the Ptolemaic Dynasty women finally rose to become equal co-rulers with men and even challenging them in order to become their respective consorts. This was due to a progressive improvement of the already high status of women in the Egyptian society, as well as to the religious principle of balance (Maat) between male and female. In Nubia, Queens like Amanishakheto and Amanitore were crowned alongside Kings at Dangeil and had both their pyramids at Meroë with the same height and side by side, and exercised power at the same level, even commanding armies. In Ethiopia, Kandakes also reached and hold this or a similar status.

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