Robert Baratheon was the ruler of the Seven Kingdoms, formally styled as Robert of the House Baratheon, the First of His Name, King of the Andals and the First Men, Lord of the Seven Kingdoms and Protector of the Realm. He took the throne through conquest in the war known as Robert's Rebellion. Robert was a great warrior in his youth. He killed Rhaegar Targaryen, Prince of Dragonstone, at the Battle of the Trident. After the war, Robert married Cersei Lannister to cement an alliance with House Lannister to hold the kingdoms together, but the marriage is loveless. Robert and Cersei have three children: Joffrey, Myrcella and Tommen. Unbeknown to Robert, all three were actually fathered by Cersei's twin brother, Jaime Lannister.
Robert found the winning of his kingdom far more fulfilling than the running of it, and spent much of the next seventeen years whoring, drinking and hunting. So it is his small council that is delegated the tedious tasks of ruling. He is a childhood friend of Eddard Stark and considers him his true brother. He names Ned Hand of the King when the previous Hand dies in mysterious circumstances. Eddard launches an investigation and discovers that his predecessor was scrutinising the parentage of Cersei's children. Fearful of exposure, Cersei instructs Robert's squire, Lancel Lannister, to give him too much wine while hunting. Robert is fatally wounded by a boar and succumbs to his injuries soon afterwards. Robert names Eddard protector of the realm just before his death. Cersei then ignores the proclamation, has Eddard arrested, and seizes the throne for her son, Joffrey. This dispute leads to the War of the Five Kings.
Robert is the first son of Steffon Baratheon and Cassana Baratheon, and has two younger brothers, Stannis and Renly. Steffon was the head of House Baratheon and Lord Paramount of the Stormlands. The Stormlands are one of the constituent regions of the Seven Kingdoms and House Baratheon is one of the Great Houses of the realm. His parents died in his youth when their ship was caught in a storm; Robert, standing on the walls of Storm's End with Stannis, witnessed his parents ship that was returning from Essos break up on the rocks. He inherited the lordship, and was fostered by Jon Arryn, the head of House Arryn, another Great House. Eddard Stark, the second son of House Stark, was also fostered by Jon Arryn and Robert and Eddard became as close as brothers.
Robert served King Aerys II Targaryen (known as the Mad King) as the Lord Paramount of the Stormlands. Robert was betrothed to Lyanna Stark, Eddard's sister. Lyanna was kidnapped by Prince Rhaegar Targaryen. The mad king had Eddard's father and brother killed for protesting against the kidnapping. This sparked a massive uprising against the Mad King led by Robert, Eddard and Jon Arryn. Lyanna and Aerys died during the civil war that followed. 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, Jon Arryn and Eddard Stark, believed that Robert, with his claim and charismatic personality, should be king and both stood aside.
Robert was devastated by Lyanna's death, but was urged by Jon Arryn to marry Cersei of House Lannister, making an alliance with her father, Tywin Lannister, who had joined his cause late in the conflict and delivered the capital of King's Landing to him. He named Jon Arryn as his Hand while Eddard took his father's role as Warden of the North.
Stannis fought for Robert through the war. Stannis and Robert never loved one another. Despite Stannis' service during the war, Robert made Renly the Lord of Storm's End following his victory. Renly was only a child during the civil war, so he did not fight. Stannis was made Lord of Dragonstone and served on his Robert's small council as Master of Ships. Renly later joined the small council as Master of Laws.
Robert has been the King of the Andals and the First Men and the ruler of the Seven Kingdoms of Westeros since the end of the civil war. However, he is more concerned with drinking, whoring and hunting than with the minutiae of ruling his kingdom. He revels in the glory days of the rebellion. He leaves the running of the kingdom largely his small council, led by Jon Arryn. King Robert also loves to throw events such as tournaments at which he spares no expense. Unfortunately, after seventeen years this has left the realm deeply in debt, for a shocking six million Gold Dragons, half of that to House Lannister. He apparently has three children with Cersei: Joffrey, Myrcella and Tommen. Unbeknownst to Robert all three were actually fathered by Cersei's twin brother Jaime Lannister. Robert has also fathered several illegitimate bastards. He has an unacknowledged bastard son named Gendry fathered on a tavern wench. He has an unacknowledged bastard daughter named Barra fathered on the prostitute Mhaegen. He has at least four other unacknowledged bastards fathered with various women in the city of King's Landing alone.
Jon Arryn began to investigate the lineage of Cersei's children, comparing their appearance to Robert's bastard offspring. He died under mysterious circumstances shortly after beginning his investigation. Robert has decided to ride north to Eddard's keep Winterfell to name him as Jon Arryn's replacement.
The royal party arrives in Winterfell and Lord Eddard presents his household to King Robert. After initial greetings, Robert demands to see the crypts and pay his respects, stoking Queen Cersei's impatience. In the crypts Robert offers prayers to a statue of Lyanna Stark. He tells Eddard that in his dreams he kills Rhaegar Targaryen every night anew, but Eddard replies that House Targaryen is destroyed. "Not all of them," Robert counters. Robert formally offers Eddard the role of Hand of the King, telling him that he needs someone to run the kingdom and revealing that he is fearful of betrayal from within his court. Eddard asks for time to think about it. Robert agrees but offers a sweetener: the hand of his son Joffrey in marriage to Eddard's daughter Sansa. A great feast is held in honor of the king's visit to Winterfell. The next morning Eddard and Robert go hunting and Eddard accepts Robert's offer, with Robert stating that Ned is a loyal friend, the last one he's got.
The parties depart Winterfell. Days later, on the Kingsroad south to the capital, Robert calls a halt to discuss some newly-arrived dire news with Eddard. Robert's spies have learned of Daenerys Targaryen's marriage to Khal Drogo whose khalasar is reported to number over one hundred thousand people. Eddard points out that the Dothraki cannot cross the Narrow Sea, as they have no ships, but Robert is concerned that the Seven Kingdoms will soon face another war.
On the Kingsroad, the royal party reaches the Crossroads Inn, a noted stop on the way south to the capital. Joffrey is injured by Nymeria, a direwolf belonging to Ned's younger daughter Arya during the halt. Arya is brought before Robert and truthfully blames Joffrey for instigating the incident but Joffrey's falsified version of events is supported by Sansa. Robert is furious that a minor fracas has become a major incident with his wife and his new Hand accusing one another's children; he also appears to exhibit disdain towards Joffrey over the fact his son was beaten and disarmed by a girl several years his junior. He decides to let Ned discipline Arya whilst he will do the same to Joffrey, but to appease his Queen he agrees that a direwolf must be executed. When Nymeria cannot be found, Robert commands that Sansa's wolf Lady must be killed instead.
On his return to King's Landing Robert orders a tournament to celebrate Eddard's appointment as King's Hand. He avoids the small council meetings where discussion of the kingdom's mounting debts and the difficulty of paying for the tournament are raised. Robert swaps old war stories with Ser Barristan Selmy, a distinguished and famous knight and Lord Commander of the Kingsguard and Jaime Lannister, whilst also humiliating his 'useless' squire, Lancel Lannister. Robert enjoys the attentions of at least four women in his chambers. Jaime Lannister, left guarding his room outside, is infuriated by the insult done to his sister by this, and vents about it to Jory Cassel.
Robert learns that Daenerys is pregnant and orders that she and her brother Viserys Targaryen be assassinated. Eddard disagrees with the decision, and resigns as Hand, enraging Robert. Later, Cersei asks the King if it was wise to lose Eddard in this way and they discuss their marriage. Robert tells her he could never love her due to his feelings for Lyanna. Robert's brother Renly reports that Robert is planning a big hunt and has asked Renly to accompany him, a prospect Renly dreads.
Robert and Cersei visit Eddard as he recovers at the Tower of the Hand, from wounds sustained fighting Jaime and his guards. Cersei is furious with Eddard for having her brother Tyrion arrested and for fighting with Jaime, but Eddard is unrepentant. She wants Robert to take action against him, but Robert refuses to condemn him, without hearing Eddard's side, and tells her to be silent. When Cersei protests further, and calls Robert a woman, he hits her. She says that she will wear the bruise with honor. Robert tells her to be silent, or he will honor her again, and Cersei leaves in anger. Afterwards, Robert restores Eddard to his position as King's Hand, and tells him not to quit again, or he will give the position to Jaime Lannister. He tells Ned to end the animosity between House Stark and House Lannister, as strife between the two houses could lead them into war, and that he is leaving on a hunt in the Kingswood and wants the realm at peace by the time he returns. Robert goes hunting, taking Selmy, Lancel and Renly with him. Being supplied with wine by Lancel, Robert becomes drunk and nostalgic, and Renly becomes annoyed with Robert for glorifying the "good old days" and leaves the hunt to return to the castle. Robert is badly wounded whilst trying to kill a boar while hunting. He is taken back to the capital and on his deathbed tells Joffrey that he wishes he could have been a better father to him. After Robert commands everyone to leave, he names Ned as Lord Regent and Protector of the Realm. Eddard has learned that Joffrey, Myrcella and Tommen are not Robert's children, but are instead the product of incest between Cersei and her twin brother Jaime, but is unable to tell the dying Robert this. Robert also asks him to cancel the attempt on Daenerys Targaryen's life but it comes too late to stop the attempt on Daenerys' life. After Robert's death, Cersei destroys the proclamation of Eddard as Regent and Protector of the Realm and has Eddard arrested. Renly also flees the city, after telling Eddard that he would make a better king than his and Robert's other brother (and the rightful heir), Stannis. Robert's death sparks the War of the Five Kings with both of his brothers, Joffrey, Balon Greyjoy, and Robb Stark crowning themselves as kings.
At some point prior to his death (possibly as he lay mortally wounded after the boar hunt), Robert specified that he did not want to be buried in the Great Sept of Baelor in King's Landing, where the remains of previous kings from the Targaryen dynasty are interred. Instead, as per Robert's instructions he was buried alongside his forefathers at his family's ancestral castle, Storm's End.
After Rhaegar Targaryen kidnapped his fiancée, Lyanna Stark, Robert Baratheon led a rebellion against the Mad King Aerys Targaryen. Aided by his childhood friend, Lyanna's brother, Ned Stark, Robert was subsequently crowned king. When he died suddenly in a hunting accident, his heir Joffrey claimed the throne.