Robert's Rebellion

Robert's Rebellion, also called the War of the Usurper by those loyal to the old dynasty, was the great war that overthrew House Targaryen after nearly three centuries of rule and set Robert Baratheon upon the Iron Throne. It took its name from Robert, Lord of Storm's End, whose claim through his Targaryen grandmother and whose prowess in battle made him the figurehead and ultimate victor of the uprising. The war is reckoned to have taken place some fifteen years before the events that begin the War of the Five Kings.

Causes

The roots of the rebellion lay in the conduct of Prince Rhaegar Targaryen and the madness of his father, King Aerys II. Rhaegar carried off Lyanna Stark, betrothed of Robert Baratheon and sister to Eddard Stark -- an act the realm took for an abduction. When Brandon Stark, Lyanna's brother, rode to King's Landing to demand her return, the Mad King had him and his father, Lord Rickard Stark, cruelly put to death. Aerys then demanded that Jon Arryn surrender his wards, Eddard Stark and Robert Baratheon, for execution. Jon refused and called his banners instead, and the realm went to war.

The War

The rebels -- the houses of Baratheon, Stark, Arryn, and Tully, bound together by marriage and fosterage -- rose against the crown. Robert won renown at the Battle of the Bells in the riverlands, but the decisive clash was the Battle of the Trident, where Robert met Rhaegar in single combat amid the fords and slew him with his warhammer, breaking the loyalist cause.

While the war was decided at the Trident, Tywin Lannister brought the long-aloof might of House Lannister into the war on the rebel side at the last, and his men sacked King's Landing. The Mad King was slain by his own Kingsguard, Jaime Lannister, earning him the name Kingslayer, and the Targaryen children of Prince Rhaegar were murdered.

Aftermath

Robert Baratheon was crowned king, founding the Baratheon dynasty. He wed Cersei Lannister to bind the powerful west to his new reign. Eddard Stark rode to the south to find his sister Lyanna dying, and returned north with a bastard son, Jon Snow, whose true parentage he never spoke of. The surviving Targaryen children, Viserys and the infant Daenerys, were spirited across the Narrow Sea into exile.

Significance

Robert's Rebellion ended the rule of the dragon-kings and reshaped the balance of power in Westeros, but it settled nothing for long. The unresolved tensions it left behind -- the exiled Targaryens, the overmighty Lannisters, and the unspoken secrets of Lyanna's death -- would in time ignite the wars that consume the realm.