Orys Waters, King Axel's baseborn son conceived with Sarella Martell, legitmized by his deathbed degree. Backed by Lord Lorent Tyrell of Highgarden. After the Great Council of 398AC, Orys wins by majority vote, three to two, and is elected as the next ruler upon the Iron Throne. Following an uprising led by House Lannister and House Stark, Orys Waters was slain in the siege of King's Landing.
Beron Baratheon, the son of King Axel's brother Jon, Hand of the King. Heir presumptive for the most of his life and Lord of Dragonstone. Backed by Lord Lyonel Lannister of Casterly Rock. Following an uprising led by House Lannister and House Stark, Beron Baratheon took the Throne and is remained King until the conclusion of the Fourth Targaryen Rebellion.
Aelyx Targaryen, descendant of the Dragonkings. The Last Dragonrider and wielder of the Valyrian steel sword Blackfyre, he is currently situated in Essos after the events of the Third Targaryen Rebellion. Taking advantage of the vicious infighting between Orys and Beron, Aelyx initiated the Fourth Targaryen Rebellion, eventually besting Beron Baratheon to claim the throne for himself.