Trystane Truefyre, The Flea Bottom Prince.

The first was Trystane Truefyre, a squire to a disreputable hedge knight named Ser Perkin the Flea, who Ser Perkin declared was the natural son of Viserys I. After the storming of the Dragonpit and Rhaenyra's flight, the Shepherd and his mob ruled much of the city, but Ser Perkin installed Trystane in the abandoned Red Keep and began to issue edicts. When Aegon II eventually retook the city, Trystane begged the boon of knighthood before he was executed, and this he received.