Aenar Targaryen

Aenar Targaryen, known as the Exiled, is a former member of House Targaryen and a Dragon Lord of Valyria who lived during the time of the Scourge. 

His daughter Daenys the Dreamer predicted the Scourge twelve years before it happened, so Aenar sold all his possessions and took his wives, children, family, slaves, and the five dragons of his house (including Balerion) to Westeros on the island of Peyredragon.

His rivals and other Valyrian nobles generally saw this as cowardice, but after the Scourge, the Targaryens were the only line of dragon lords to survive. After his death, his son, Gaemon, Daenys' husband, took over the leadership of the house.