Question: who are rhaegar and lyanna?
Answer: Lyanna Stark's abduction by the Crown Prince Rhaegar Targaryen was one of the leading causes of the rebellion. Lyanna was betrothed to Lord Robert Baratheon, the young head of House Baratheon, while Prince Rhaegar, heir to the Iron Throne, was married to the Dornish princess Elia Martell per a political arrangement.