Aegon I Targaryen, also known as Aegon the Conqueror, was the first king of the Targaryen dynasty in Westeros. He united the Seven Kingdoms through conquest, beginning in Aegon's Landing, where he established the Iron Throne. His reign marked the start of the Targaryen rule, which lasted nearly 300 years. Aegon I was known for his military prowess and strategic marriages, including his union with his sisters, Visenya and Rhaenys. He rode the dragon Balerion the Black Dread, which helped him in battles. Aegon's legacy includes the establishment of the Targaryen bloodline and the famous Targaryen motto, "Fire and Blood."