Robert Baratheon

Robert Baratheon was the lord of the Stormland region of Westeros, one of the Seven Kingdoms ruled by the Targaryen Dynasty since the conquest about 300 years before Robert's birth. As a young man, Robert fell in love with Lyanna Stark, and was infuriated to learn that she was, at least according to Stark and Baratheon accounts, kidnapped by Targaryen Prince Rheagar. Lord Rickard Stark and his son Brandon rode for King's Landing to demand justice from King Aerys Targaryen, but Aerys, who would later become known as the "Mad King" accused them of plotting to assassinate Rheagar, and had Rickard hung over a fire and roasted alive, while Brandon had a rope tied around his neck, and a sword placed just out of his reach. Brandon tried to reach the sword, but ended up strangling himself in the efforts as his father burned to death.

This drove Robert and Eddard "Ned" Stark to rebel against Aerys. During rebellion, Robert always found from the front lines, most notably at the Battle of the River Trident, in which Robert personally killed Rhaegar Targaryn with his warhammer.

Robert's armies, along with those of Tywin Lannister, who had recently betrayed the Targaryens, laid siege to and subsequently sacked the capital of King's Landing. The Lannister armies raped and murdered countless civilians, the most infamous of these incidents being the rape and murder of Eila Martell, followed by the murder of her children by Gregor Clegane. As his kingdom crumbled around him, Aerys ordered the city set alight using wildfire, a highly flammable substance similar to real-world Greek Fire, believing the inferno would transform him into a dragon.

Kingsguard knight Jaime Lannister refused to let this happen, and killed Aerys, betraying his sacred oath to protect the king, though he was later pardoned by Robert. After the rebellion, Robert claimed the throne, as he was most closely related to the vanquished Targaryen, and in any case, the other rebel leaders refused the throne.

After the rebellion, Robert married Cersei Lannister, Lyanna having been killed in the war, for purely political reasons, having never loved her. Because of this, Robert never realized that his children, Joffrey, Myrcella, and Tommen were not, in fact, his, but rather the result of an incestuous relationship between Jaime and Cersei Lannister, as Robert never paid much attention to his wife, preferring drinking, womanizing and hunting.

This fact was discovered by Eddard Stark, at about the same time Robert is killed by a boar on a hunting trip, and Joffrey takes the throne. Eddard attempt to stop Joffrey's ascension, but he is betrayed by his allies. Joffrey later has Eddard publicly beheaded.

The deaths of both Robert and then Eddard spark the War of the Five Kings, between Joffrey, rival claimants to the throne Renly and Stannis Baratheon, as well Robb Stark and Balon Greyjoy, Lords of the North and Iron Islands respectively, both of whom declare their independence from the Seven Kingdoms.