A Song of Ice and Fire is an HBO TV miniseries which serves as a prequel to the hit series Game of Thrones. The miniseries documents the end of the reign of Aerys Targaryen, the "Mad King", and Robert's Rebellion. With the exception of Charles Dance, none of the actors from Game of Thrones reprise their characters, being that they are much younger than in the series.
- Douglas Booth as Eddard 'Ned' Stark- A member of House Stark, which rules Winterfell. After his sister Lyanna is kidnapped by Prince Rhaegar Targaryen, his brother and father are in turn murdered by Rhaegar's father, King Aerys Targaryen, Ned joins his good friend Robert Baratheon in a rebellion against the Iron Throne.
- Allen Leech as Robert Baratheon- The heir to House Baratheon of Storm's End. He is originally betrothed to marry the beautiful younger sister of his good friend, Ned Stark, but she is kidnapped by Prince Rhaegar, which infuriates Robert to the point of declaring war against King Aerys.
- Jared Harris as Jon Arryn- The Lord of The Vale and Warden of the East. He fostered both Eddard Stark and Robert Baratheon for the majority of their childhoods, and rises up with them in rebellion against the Iron Throne.
- Tom Felton as Prince Rhaegar Targaryen- The crown prince of the seven kingdoms of Westeros and heir to the Iron Throne. After being stunned by the beauty of Lyanna Stark, he abducts her and thus inadvertently starts a rebellion against his father led by Lyanna's betrothed as well as her brother.
- Tim Roth as King Aerys II Targaryen- The King of the Andals and the First Men, Lord of the Seven Kingdoms, and Protector of the Realm. Nicknamed the "Mad King" after succumbing to madness and infuriating the people of Westeros. After allowing his son's abduction of Lyanna Stark, and murdering her father and brother when they arrived to rescue her, Robert Baratheon and Eddard Stark start a rebellion against his rule.
- Hugh Mitchell as Jaime Lannister- The youngest knight ever to be on a kingsguard, and the eldest son of Tywin Lannister, the wealthiest man in Westeros. Young, arrogant, and stubborn, he originally firmly believes in King Aerys and the vows he took. However, after witnessing firsthand how sadistic the king can be, he begins to question his vows and his role in the Mad King's tyrannical rule.
- Kaya Scodelario as Lyanna Stark- The beautiful younger sister of Eddard Stark, who is betrothed to marry Robert Baratheon. However, she is abducted by Prince Rhaegar who lusts for her, thus beginning Robert's Rebellion.
- Emily Berrington as Catelyn Tully- The eldest daughter of Lord Hoster Tully, Lord of Riverrun. She is betrothed to marry Brandon Stark, but he is murdered by the Mad King once he goes to the capital to try and rescue his sister. As a result, she marries Brandon's younger brother Eddard in order to secure an alliance with the rebellion and the Tullys. While Ned is away at war, she learns that she is pregnant with his child.
- Charles Dance as Tywin Lannister- The Lord of Casterly Rock and Warden of the West, as well as the wealthiest man in Westeros and former Hand of the King for King Aerys. Though he hates the Mad King, he is hesitant to get his house and bannermen involved in the rebellion for fear facing the wrath of the Mad King. Dance is the only actor to reprise his role from Game of Thrones.
- Tamzin Merchant as Cersei Lannister- Lord Twyin's only daughter and Jaime's twin sister, as well as secret lover. Tywin had originally planned to have her marry Prince Rhaegar, but the Mad King refused the offer in an attempt to spurn the Lord Lannister.
- Peter Mullan as Hoster Tully- The Lord Paramount of the Riverlands, who forges an alliance with Robert's Rebellion after Lords Stark and Arryn wed his two daughters.
- Jessie Cave as Lysa Tully- The younger daughter of Lord Hoster Tully, who weds the much, much older Jon Arryn while her sister weds the more favorable Ned Stark.
- Martin Kemp as Rickard Stark- Lord of Winterfell and Warden of the North, as well as father of Brandon, Eddard, Lyanna, and Benjen Stark. He is murdered by the Mad King when he tries to ransom the release of his eldest son and daughter.
- Sean Biggerstaff as Brandon Stark- The eldest of Rickard Stark's children and the heir to Winterfell. He rides to King's Landing and demands the release of his sister, Lyanna, after she is abducted by Prince Rhaegar, but he is taken prisoner by the Mad King, and later killed along with his father.
- Michelle Vargas as Elia Martell- The wife of Prince Rhaegar.