Who were Rhaegar and Lyanna? Rhaegar Targaryen was the son of Aerys II Targaryen – better known as the Mad King – and older brother to Daenerys. Lyanna Stark was the only daughter of Rickard Stark, and younger sister to Ned. Rhaegar was actually married to Elia Martell, while Lyanna was betrothed to Robert Baratheon.