“In that darkness, the White Walkers came for the first time. They swept through cities and kingdoms, riding their dead horses, hunting with their packs of pale spiders big as hounds”
- Old Nan
According to legends, the White Walkers came from the Lands of Always Winter six or eight thousand years ago, and brought with them cold and darkness that lasted a generation: the Long Night. They resurrected dead men and animals to serve them.
While having an overall humanoid appearance, White Walkers differ greatly from humans. They are taller than humans and have long wispy white hair and also commonly a white beard. They have pale grey-white skin which is sinewy and stretched taut across their frames, giving them a somewhat gaunt and mummified appearance despite their overall bulky size. White Walkers are much stronger than humans and are capable of sending large men reeling back several feet with a single blow. Their most notable trait, however, is their glowing blue eyes
The White Walkers swept through the world with their large army, taking over the biggest of kingdoms and adding more to their army. However, in the Battle for the Dawn, they were finally defeated, by the first men of the Night's Watch and the children of the forest, an alliance made possible by the last hero, known as Azor Ahai.
“Robert was betrothed to marry her, but Prince Rhaegar carried her off and raped her. Robert fought a war to win her back. He killed Rhaegar on the Trident with his hammer, but Lyanna died and he never got her back at all.”
- Brandon Stark
Aerys II Targaryen was King of the Andals and the First Men and the last member of House Targaryen to sit on the Iron Throne. The King is nicknamed the Mad King because his reign became increasingly erratic and murderous. Consequently, tensions between House Targaryen and several other Great Houses began to rise.
The brutal fallout from Prince Rhaegar's alleged abduction of Lyanna Stark of Winterfell saw many noble houses in the realm rebel against his rule. In truth, however, Lyanna had not been kidnapped; she had eloped with Rhaegar, who had the High Septon issue an annulment to his marriage with Elia Martell. The rebellion climaxed with the Battle of the Trident, when the rebel armies destroyed the royalist host and killed Prince Rhaegar.
Lannister forces, apparently having decided to support the king, arrived at King's Landing to help defend the capital, but then turned on the Targaryens, brutally sacking the city and killing King Aerys II and Rhaegar's children. Aerys's other heirs, Viserys and Daenerys Targaryen, were spirited to safety across the sea by Targaryen loyalists before the garrison of Dragonstone (where the two children were being kept for their safety) could hand them over to Robert Baratheon. House Tyrell, whose main force had been held up in a lengthy siege at Storm's End, proclaimed loyalty to Robert soon after the sacking of King's Landing when Eddard Stark arrived with an army to relieve the siege.
After his successful rebellion, Robert became the King of the Seven Kingdoms. He appointed Jon Arryn, husband of Lysa Arryn of the Vale, as the hand of the King. But later on, during his years of reign - Jon Arryn is murdered. And Robert wants to find a suitable replacement for his Hand.