The fifth king in the Targaryen dynasty, Viserys I sits on the Iron Throne when we join "House of the Dragon." He is the son of Baelon Targaryen and grandson of Jaehaerys I, known as "the Conciliator," and is descended from Aegon I, the Conqueror, who took over Westeros and launched the royal Targaryen dynasty generations earlier. Like others in his family, Viserys is a dragonrider. In fact, his dragon is Balerion, the same dragon Aegon I rode; after Balerion's death during Jaehaerys's reign, Viserys does not seek a new dragon. Viewers see Balerion's skull in the Red Keep during "House of the Dragon."
Viserys's reign is plagued by significant questions over who is to succeed him. His first marriage to Aemma Arryn only produces one surviving heir: his daughter, Rhaenyra. Although he intends for Rhaenyra to succeed him on the throne, his remarriage complicates things. His second marriage, to Alicent Hightower, produces three sons and a daughter, and the eldest son, Aegon, who is ultimately crowned King by the greens after his death. The Targaryen family tree branches out from his complicated family.