- "My sister loved him. She bore his children. Swaddled them, rocked them, fed them at her own breast. Elia wouldn't let the wet nurse touch them. And beautiful, noble Rhaegar Targaryen... left her for another woman."
- ―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. 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.
In truth, Lyanna had not been kidnapped. She had fallen in love with Rhaegar and had ran off with him to Dorne, where the two were secretly married.
For unknown reasons, the heir to the Iron Throne, Prince Rhaegar Targaryen, abducted Lyanna Stark, the daughter of Lord Rickard Stark, the Lord of Winterfell, Lord Paramount of the North, and Warden of the North, and hid her away in Dorne. This event was extremely scandalous as Lyanna was the daughter of the Warden of the North and was betrothed to Lord Robert Baratheon, the Lord of Storm's End and Lord Paramount of the Stormlands, while Rhaegar himself was already married to Princess Elia Martell, with whom he had a daughter and a son, Rhaenys and Aegon.
After Lyanna's abduction, her older brother Brandon, who had been on his way to Riverrun to wed Catelyn Tully, rode instead to King's Landing demanding that King Aerys II Targaryen, Rhaegar's father, have Lyanna returned and Rhaegar punished. He was taken prisoner and charged with treason, at which point his father, Rickard Stark, was summoned to ransom him. Aerys's councilors urged him to pardon Brandon Stark, as Rhaegar had stolen his sister and was the heir of the Warden of the North. However, the Mad King, in his delusion and insanity, had them both put to death.
The Mad King then had a raven sent to Lord Jon Arryn, the Lord of the Eyrie, Lord Paramount of the Vale, and Warden of the East, demanding that he hand over Robert Baratheon and Eddard Stark, Rickard's second son and Brandon's younger brother, both of whom he had been fostering at the Eyrie. Instead, Jon Arryn rallied his bannermen and rose up in rebellion against the crown. He then sent Robert back to the Stormlands and Eddard back to the North to do the same. Robert's Rebellion had begun.
Rhaegar left a pregnant Lyanna at the Tower of Joy in the Red Mountains of Dorne when he returned to the capital to personally lead the fight against Robert Baratheon. However, at the Trident in the Riverlands, the royalist army was smashed by the united rebel army, and Rhaegar himself died at the hands of Robert at what became known as the Battle of the Trident.
After the Sack of King's Landing by Lord Tywin Lannister, where he had Ser Gregor Clegane murder the rest of Rhaegar's family, Ned Stark rode south with Howland Reed and a small party of Northmen to the Tower of Joy to recover his sister, who was still set to marry Robert. When Ned, Howland, and the group arrived, however, they were confronted by the last of the Mad King's Kingsguard, Ser Arthur Dayne and Lord Commander Gerold Hightower. Ned and Howland survived the duel, defeating both Kingsguard albeit dishonorably out of desperation to find Lyanna.
Ned found his sister inside the tower, where she was dying after giving birth to Rhaegar's last son. Lyanna begged Ned to protect her newborn son, who Robert and Tywin likely would have killed given his Targaryen heritage. Ned promised his sister that he would protect him as she died, raising his Targaryen nephew as his own bastard son at Winterfell, Jon Snow. Eddard would return to Winterfell to find Catelyn Tully, who had been wed to Eddard after Brandon's death, holding their first son, Robb Stark, while Eddard presented his nephew - as his bastard son fathered on campaign, something that stained his honor and marriage and haunted him and Catelyn for the rest of their days.
Many years later, it is pieced together by Bran Stark and Samwell Tarly at Winterfell that Robert's Rebellion, which had resulted in the greatest shift of power in the Seven Kingdoms of Westeros since Aegon's Conquest, was built on a lie: Rhaegar and Lyanna had loved each other and had eloped together. Bran discovers that Jon's real name is Aegon Targaryen, and tells Sam that "Jon" is the rightful heir to the Iron Throne, not his aunt Daenerys.
In the books
In the A Song of Ice and Fire novels, Lyanna and Rhaegar first encountered each other at a tourney at Harrenhal in 281 AC, the Year of the False Spring. The details of this are revealed in the story of the Knight of the Laughing Tree, which Meera Reed tells Bran Stark as they make their journey to the Wall.
Lyanna attended the tourney with her brothers. They met Howland Reed for the first time when Lyanna rescued him from a group of bullying squires. The tourney was attended by several important figures such as King Aerys II Targaryen, Prince Rhaegar and his wife Elia, Lyanna's betrothed Lord Robert Baratheon, Lord Mace Tyrell, Prince Oberyn Martell and Lord Jon Connington. During the feast Rhaegar, a noted musician, performed a sad and beautiful song that made Lyanna sniffle; when her younger brother Benjen teased her for crying, she poured wine over his head.
Rhaegar went on to win the tourney, unseating Lyanna's older brother Brandon, Lord Yohn Royce, Ser Arthur Dayne and Ser Barristan Selmy. Then the victorious Rhaegar urged his horse past his Elia, laying the blue winter rose laurel in Lyanna's lap and declaring her the Queen of Love and Beauty, to the shock of everyone present. The lords who conspired against Rhaegar used this act as proof that the crown prince was conspiring against Aerys. They claimed that he insulted his wife by crowning Lyanna as a political move to gain House Stark's assistance in his supposed effort to usurp his father. But if that had been his intent, it failed because the act upset both Brandon and Eddard Stark, who took it as a slight against Lyanna's honor. Brandon had to be restrained from confronting the prince and Robert Baratheon claimed that Rhaegar was only paying Lyanna her due, while keeping his true resentment over the incident to himself.
Though the events of the tourney are regarded as the beginning of the Rebellion, according to The World of Ice and Fire, Rhaegar and Lyanna are not known to have encountered each other again until a year later, after the birth of Rhaegar's son with Elia, Prince Aegon Targaryen. While in the Riverlands, Lyanna was kidnapped by Rhaegar with the help of half a dozen companions, including Arthur Dayne and Oswell Whent. Rhaegar carried her off to Dorne and raped her. When Brandon heard what happened, he and his companions rode to King's Landing and demanded his sister's return, while also threatening Rhaegar. Aerys took them all prisoner and charged them with treason. When their fathers, including Rickard Stark, arrived upon the king's command, Aerys had them all killed. The king then demanded that Jon Arryn send him the heads of his foster sons, Eddard Stark and Robert Baratheon. Jon responded by raising his banners, bringing an official start to the Rebellion.
Barristan Selmy is convinced that "Prince Rhaegar loved his Lady Lyanna," though that love sent thousands to their respective deaths.
According to Viserys Targaryen, Rhaegar was simply not happy with his marriage, claiming that if Rhaegar was happy with Elia, he would not have needed Lyanna. He once blamed their sister Daenerys Targaryen for being born too late to marry Rhaegar, reasoning that a happily married Rhaegar would need neither Elia nor Lyanna; Daenerys countered that, by the same logic, it was the fault of Viserys that he was not a girl, because then he would be the sister destined for Rhaegar. Viserys beat her cruelly for her insolence.
Cersei Lannister, who was infatuated with Rhaegar, believes that the madness led King Aerys to deny Lord Tywin's proposal of marriage between her and the crown prince; Cersei thinks that if she herself had only married Rhaegar as the gods had intended, he would have been satisfied in his queen and never have looked twice at the "wolf girl". Kevan also thinks that Cersei would have been a better match for Rhaegar, for similar reasons.
Abduction of Lyanna Stark · Execution of Rickard and Brandon Stark