The Tanwa-Seynorral of the Caeliar was the Caeliar equivalent to a head of government. The phrase was an idiom that translated to "first among equals" (a phrase similarly used to refer to Earth prime ministers in the pre-Unification era). The tanwa-seynorral often served as a representative of and leading figure in the Caeliar Quorum. (ST - Destiny novel: Gods of Night)
In 2168, the Caeliar Tanwa-Seynorral was Ordemo Nordal. His term of office extended through the temporal displacement of Axion to 1519 and lasted at least until 2381. (ST - Destiny novels: Mere Mortals, Lost Souls)