Wikipedia
Tawananna is the title for the queen of the Hittites, the king's consort, as long as she was living. Upon her death the title Tawananna passed to her daughter or the new king's consort, whichever was available to ascend. The Hittites were ruled by a theocratic monarchy, in which the king's heir's wife did not succeed as Tawananna until the death of the former Tawananna.
The Tawannana also had the duty of ruling when the King was away fighting in battle and was the High Priestess while the king was High Priest of the Hittite Empire. The main duties of Tawanannas were mainly religious. An example of a Hittite Tawananna was Puduhepa, wife of Hattusili III. After the death of Hattusili III, Puduhepa took on the responsibility of communicating with the Egyptian royal family and rulers of the Hittite vassal states.
Because the title was reserved, it meant no Tawananna began the Ceremony of Enthronement to her king, until just after the previous Tawannanna died. This often resulted in bitter rivalries between newly appointed queens and their stepchildren who would inherit the true power of the kingdom. Such an incident is noted in the translated version of a bilingual Akkadian-Hittite cuneiform tablet, the Testament of Hattusili.
Tawananna is also a personal name of one queen.