Robert's Rebellion

Robert's Rebellion was a civil war amongst the Great Houses of Westeros that took place approximately seventeen years before the TV series began, and lasted about one year. It displaced the royal House Targaryen and saw most of its members wiped out, with only two survivors who fled into exile across the sea. House Baratheon became the new royal house after the war's conclusion.

Background
Aerys Targaryen, the Second of His Name, was the King of the Seven Kingdoms and the last member of House Targaryen to sit the Iron Throne. Nicknamed the Mad King, his reign became increasingly erratic and murderous. As a result, tensions between House Targaryen and several other Great Houses began to rise. A final round of blood-letting, unleashed when his son Prince Rhaegar kidnapped Lyanna Stark of Winterfell, saw many Houses in the realm rebel against his rule.

Lyanna was a prominent noblewoman as the daughter of Rickard Stark, Lord Paramount of the North. She was also betrothed to Robert Baratheon. Robert served Aerys as the Lord Paramount of the Stormlands prior to the abduction. House Stark and House Baratheon were the first to protest Rhaegar's actions. Brandon Stark demanded justice from Aerys in person. Aerys had him arrested for treason and then offered to ransom him to his father Rickard. Aerys summoned Rickard to court and when he arrived publicly executed both father and son. The brutal murder of Brandon and Rickard engendered much sympathy for the rebels and many houses joined their cause.

Jon Arryn was a natural ally to the rebels. He was the Defender of the Vale and a respected nobleman. Both Rickard's second son Eddard Stark and Robert fostered with him as children and became close friends. When Aerys demanded that Eddard be turned over to the King's justice, Lord Jon rebelled, calling his banners to war. The rebels forged an alliance with House Tully through marriage, with Eddard married to Catelyn Tully and the then-elderly Jon to the young Lysa Tully.

Stannis Baratheon fought for his elder brother Robert during the war. Aerys used his allies in House Tyrell to besiege Stannis at Storm's End for much of the war. Stannis's force was rescued from starvation by the smuggler Davos Seaworth, who brought a ship full of onions into the castle.

Rhaegar was killed during the fighting at the Battle of the Trident. Robert slew Rhaegar personally. The site of his death is now called the Ruby Ford because it is believed to be scattered with rubies from his armor.

Rhaegar's wife Elia of House Martell was kept in King's Landing by Aerys to ensure the Martell's loyalty during the conflict. Aerys was betrayed by his allies in House Lannister. He was slain by his Kingsguard Ser Jaime Lannister. His final words were "Burn them all." The gates of King's Landing were opened to the Lannister armies and they sacked the city. Elia was raped and murdered by Ser Gregor Clegane during the Sack of King's Landing. Both of her children were also killed.

Robert claimed the Iron Throne because he started the war and killed Prince Rhaegar personally. Robert also had the best claim to the throne as a result of being related to the Targaryens of old through his mother's side. The other leaders of the rebels both refused the throne. Robert was devastated by Lyanna's death but married Cersei Lannister in thanks for her father joining his cause late in the conflict and delivering the capital of King's Landing to him. Tywin remained the Lord Paramount of the Westerlands. He named Jon Arryn as his Hand while Eddard took his father's role as Warden of the North. House Tyrell, House Martell and House Greyjoy swore fealty to Robert to retain their pre-war positions maintaining the Seven Kingdoms under their new royal house.

Queen Rhaella fled to the Targaryen's ancestral seat on the island of Dragonstone. She was accompanied by her son Viserys Targaryen and was pregnant. Rhaella died soon after giving birth to Daenerys Targaryen. The children were taken into exile in the Free Cities, by loyal retainers. Stannis went on to conquer Dragonstone and was made Lord of Dragonstone.

In the books
In the A Song of Ice and Fire novels, this civil war took place between sixteen and fourteen years before the beginning of the novels. In the books the conflict is also called the War of the Usurper by Targaryen loyalists.

The war was sparked when Prince Rhaegar Targaryen kidnapped Lyanna Stark. When Lyanna's father and eldest brother protested this act to King Aerys II Targaryen, the Mad King had them both killed in front of the entire Royal Court. Aerys then called for the heads of Lyanna's betrothed, Robert Baratheon, and her second brother Eddard Stark, who were under the care of Jon Arryn. Lord Arryn raised his banners in rebellion against these unjust acts and sent Robert and Eddard back to their lands to rally their men.

House Tully joined Robert's side after Eddard and Jon married Catelyn and Lysa Tully, respectively, whilst House Tyrell and House Martell supported the Targaryens. While House Tully did support Robert, the always fractious lords of the Riverlands were heavily divided in the war, and many stayed loyal to the Targaryens. House Lannister sat out most of the war, only entering - on Robert's side - after Robert killed Rhaegar and his victory was a foregone conclusion. It is never stated which side House Greyjoy was on, but it is possible that they did not fight at all and remained neutral, saving their strength for their failed attempt to secede outright from the realm a few years later in the Greyjoy Rebellion.

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' 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.

In the aftermath of the war it was discovered that Lyanna Stark had died, so Robert married Cersei Lannister in thanks for her father delivering him victory and to secure an alliance between the two houses.

Elia Martell's brutal murder by the Lannisters during the Sack of King's Landing earned them the lasting enmity of the Martells. As a result of Elia's unnecessary and easily avoidable murder, Dorne became a hotbed of pro-Targaryen sentiment and it took lengthy negotiations on the part of Jon Arryn for them to grudgingly swear fealty to Robert.