Maelys Blackfyre

Maelys grew up in Essos, among outlaws and free companies, carrying a reputation that followed him from birth: it was said he had devoured his twin brother in his mother's womb, and that this was why a second head grew from his neck. True or not, that story is where the name Maelys the Monstrous came from.

Command of the Golden Company wasn't given to him — he took it. He fought his own cousin Daemon for control of the company, killed his horse with a single punch, then twisted his head clean off his shoulders. From then on, the Golden Company was his.

In 258 AC, Maelys met under the Crowned Tree, in the Disputed Lands, with eight other outlaws, exiles, and sellsword captains. There they sealed an alliance, the Band of Nine, pledging to help each other build a kingdom apiece.

With that strength behind him, Maelys took and sacked Tyrosh, then the Stepstones, and proclaimed himself Maelys I Blackfyre, King of the Andals, the Rhoynar, and the First Men, Lord of the Seven Kingdoms and Protector of the Realm. Westeros began watching the east with unease.

In 260 AC, King Jaehaerys II Targaryen sent an army to the Stepstones to meet the Band of Nine in battle. Early in the war, Maelys killed Lord Ormund Baratheon, the King's Hand, with his own hands.

The war was decided when Maelys himself fell, killed in combat by a young knight of the Stormlands, Ser Barristan Selmy. His death ended House Blackfyre's claim to the Iron Throne; the rest of the Band of Nine, who had never cared much for Westeros, went back to their own affairs, and the alliance fell apart soon after.

Maelys's head was boiled, gilded, and set on a spike, as was the Golden Company's custom for its fallen captains-general.

Maelys's skull stayed with the Golden Company alongside those of earlier captains-general, larger and more misshapen than the rest, with a second, fist-sized skull beneath it: his nameless twin's. Years later, Jon Connington saw it ringing the captain-general's tent in the company's camp.

In Essos, magister Illyrio Mopatis told Tyrion Lannister that Maelys's death had ended the Blackfyre male line. That same night, Tyrion dreamed he had two heads and fought alongside Barristan Selmy and Aegor Rivers. His bones are said to have later traveled to Westeros with the Golden Company, on the campaign to crown Prince Aegon Targaryen.