The Monarchy of Rellazus was the constitutional monarchy of the Rellazi Commonwealth. In 2383, the King of Rellazus was Lemus VII Tavli of the House of Tavli, who inherited the throne from his father, Hoqab XIX Tavli and whose heir apparent was Federation Starfleet Lieutenant Commander Garoz Jerud'Lemus Tavli, who held the title of Prince of Tal Zara by virtue of being the monarch's first-born child.
The holder of the title was determined by absolute primogeniture in the high house that held the throne. If the current monarch dies with no viable heirs, then the monarchy would pass to the next eligible high house, though in centuries past the monarchy was known to be taken by force via combat between the armies of the houses. However, as of 2383, the governmental role of the monarchy had been significantly diminished and there had been no combat between the houses for at least 500 years.
By Rellazi law, all heirs to the throne were required to serve in defense of the Commonwealth. Most commonly, as in the case of King Lemus, this took the form of service in the Rellazi Home Guard. However, after Rellazus became a member of the United Federation of Planets, service in Starfleet was considered to fill that role. As of 2383, both of King Lemus' sons were officers in Starfleet while his daughter was preparing to enter Starfleet Academy. (Star Trek: Remington)