Question: why was lyanna stark in dorne?
Answer: Oberyn Martell, referring to Elia Martell, Rhaegar's wife, and his abduction of Lyanna Stark. The "Abduction" of Lyanna Stark was said to have occurred shortly before the outbreak of Robert's Rebellion. ... She had fallen in love with Rhaegar and had ran off with him to Dorne, where the two were secretly married.