Dragon royalty

The ten dragon tribes from Pyrrhia and Pantala are ruled by Dragon Queens. Only their daughters, sisters, nieces, granddaughters, or great-granddaughters can serve as potential successors to the throne, with the exceptions of RainWings, MudWings, and occasionally SandWings. Since the MudWings have a leader in the group of siblings, called the "bigwings", all sisters are loyal to her and will not challenge her for queenship as they are too loyal to their siblings.

In almost all dragon tribes, for a princess or other royal female to become queen, they must challenge the current queen to a battle to the death. Whoever wins the battle will then take (or keep) the title of queen.

Another way is for the queen to die of some other cause such as sickness (Queen Glacier), being murdered (Queen Lagoon), or in an accident (Queen Oasis). If a queen was to die without being killed in a challenge the oldest daughter would usually become the new queen. 

The RainWings have devised a way to select their queen that doesn't involve violence and killing due to their pacifist, peaceful nature. They partake in a group of activities or games that involve activities that the current queen(s) wish(es) to compete in. These include flower hunts, fruit gathering, tree gliding, scale camouflage, and venom targeting. The dragon to win the majority will become queen, as seen with Glory and her royal challenge.

The method the NightWings use to choose a queen is presumably like most other tribes, although this is not known for certain, as the books claim that the NightWings's queen system is top secret, and do not build on the information there. It is possible they had a method slightly different than the other tribes.

For the SandWings, whoever obtains and is accepted by the Eye of Onyx is the next queen of the tribe, regardless of bloodline (see Queen Thorn). Otherwise, they do it the same way as the other tribes.

The SilkWings are currently under the rule of Queen Wasp, after submitting to HiveWing rule during the Tree Wars. Their last queen, Queen Monarch, stepped down.

Dragon Kings are the husbands of the queens, excluding King Darkstalker. They don't have a lot of power, compared to queens and mostly just have their title. Known kings include King Gill, King Char, King Humpback, and King Darkstalker. They tend to have only as much power as their Queens allow them to, with Darkstalker being the exception, as he briefly ruled the NightWings alone in the old NightWing Kingdom, as well as King Gill who briefly was in charge of war while Queen Coral was keeping Anemone's egg safe. It was mentioned in Deserter that King Char only had as much power as Queen Oasis gave him and that apparently he was banished from the SandWing palace for months on end at times. It is also said that Ex-Queen Scarlet once had a husband who was king, but he died, likely due to him being her husband. The name of Scarlet's husband is unknown. 

There are no known Kings on Pantala.