A Golden Company é uma empresa especializada em vendas, baseada nas Cidades Livres, e fundada por um exilado da Blackfyre Rebellion (a história de fundo que você pode encontrar na coleção de contos "Dunk & Egg").

Eu não me lembro agora se eles já foram derrotados, mas eles são mais conhecidos por sempre honrarem seus contratos.

Spoilers para sua aliança em A Dance with Dragons :

In ADwD they are Targaryen loyalists and support the child Aegon Targaryen. As of the end of the book, we know they've successfully disembarked for Westeros.

Uma canção de gelo e fogo

A Companhia Dourada é um grupo de mercenários composto de exilados e seus filhos. Foi fundada por Aegor Rivers, "Bittersteel" , um dos grandes bastardos do rei Aegon IV Targaryen. Eles são conhecidos por nunca terem quebrado um contrato (até a seguinte citação, suponho).

"Or one. Are you aware that the Golden Company has broken its contract with Myr?"
"Sellswords break their contracts all the time."
"Not the Golden Company. Our word is good as gold has been their boast since the days of Bittersteel. Myr is on the point of war with Lys and Tyrosh. Why break a contract that offered them the prospect of good wages and good plunder?"
"Perhaps Lys offered them better wages. Or Tyrosh."
"No," she said. "I would believe it of any of the other free companies, yes. Most of them would change sides for half a groat. The Golden Company is different. A brotherhood of exiles and the sons of exiles, united by the dream of Bittersteel. It's home they want, as much as gold. Lord Yronwood knows that as well as I do. His forebears rode with Bittersteel during three of the Blackfyre Rebellions." She took Ser Arys by the hand, and wove her fingers through his own. "Have you ever seen the arms of House Toland of Ghost Hill?"
_{A Feast for Crows, The Soiled Knight}

Tyrion nos dá mais informações sobre a empresa em um de seus capítulos de POV.

The dwarf pondered that. The Golden Company was reputedly the finest of the free companies, founded a century ago by Bittersteel, a bastard son of Aegon the Unworthy. When another of Aegon's Great Bastards tried to seize the Iron Throne from his trueborn half-brother, Bittersteel joined the revolt. Daemon Blackfyre had perished on the Redgrass Field, however, and his rebellion with him. Those followers of the Black Dragon who survived the battle yet refused to bend the knee fled across the narrow sea, among them Daemon's younger sons, Bittersteel, and hundreds of landless lords and knights who soon found themselves forced to sell their swords to eat. Some joined the Ragged Standard, some the Second Sons or Maiden's Men. Bittersteel saw the strength of House Blackfyre scattering to the four winds, so he formed the Golden Company to bind the exiles together.
From that day to this, the men of the Golden Company had lived and died in the Disputed Lands, fighting for Myr or Lys or Tyrosh in their pointless little wars, and dreaming of the land their fathers had lost. They were exiles and sons of exiles, dispossessed and unforgiven … yet formidable fighters still.
_{A Dance with Dragons, Tyrion II}

É composto por 10000 guerreiros, elefantes, cavaleiros e arqueiros. O atual líder é Harry Strickland. Observe o layout do acampamento e que parece incrivelmente bem feito.

The Golden Company was ten thousand strong, seasoned and disciplined. None of them seamen, though. Griff will need to keep a sword at every throat, and should they come on Slaver's Bay and need to fight …
_{A Dance with Dragons, Tyrion VII}

They found the Golden Company beside the river as the sun was lowering in the west. It was a camp that even Arthur Dayne might have approved of—compact, orderly, defensible. A deep ditch had been dug around it, with sharpened stakes inside. The tents stood in rows, with broad avenues between them. The latrines had been placed beside the river, so the current would wash away the wastes. The horse lines were to the north, and beyond them, two dozen elephants grazed beside the water, pulling up reeds with their trunks. Griff glanced at the great grey beasts with approval. There is not a warhorse in all of Westeros that will stand against them.
Tall battle standards of cloth-of-gold flapped atop lofty poles along the perimeters of the camp. Beneath them, armed and armored sentries walked their rounds with spears and crossbows, watching every approach. Griff had feared that the company might have grown lax under Harry Strickland, who had always seemed more concerned with making friends than enforcing discipline; but it would seem his worries had been misplaced.
_{A Dance with Dragons, The Lost Lord}

O lema da Companhia de Ouro é "Nossa palavra é boa como ouro", enquanto seu grito de guerra é "Abaixo do ouro, o aço amargo", que faz referência ao seu fundador.

"Not the Golden Company. Our word is good as gold has been their boast since the days of Bittersteel. Myr is on the point of war with Lys and Tyrosh. Why break a contract that offered them the prospect of good wages and good plunder?"
_{A Feast for Crows, The Soiled Knight}

Arianne knew better. If Quentyn has the Golden Company behind him . . . "Beneath the gold the bitter steel," was their cry. You will need bitter steel and more, brother, if you think to set me aside. Arianne was loved in Dorne, Quentyn little known. No company of sellswords could change that.
_{A Feast for Crows, The Queenmaker}

Game of Thrones

A Golden Company só foi mencionada brevemente no programa. Primeiramente por Davos, quando ele sugere que Stannis deveria contratá-los, aqui ele menciona que eles são vendedores de livros.

Davos: Westeros is not the world, your grace. We need to look east for ships and men. Ten thousand skilled soldiers fight for the Golden Company.
Stannis: The Golden Company?
Davos: They've never broken a contract.
Stannis: They're sellswords!
Davos: We're willing to use blood magic to put you on the throne, but we're not willing to pay men to fight?
_{Game of Thrones, Season 4 Episode 2, "Breaker of Chains"}

Eles são então mencionados novamente por Dany para Jorah, novamente implicando que eles são vendedores.

Dany: Didn't you fight for the Golden Company before pledging your sword to my brother?
_{Game of Thrones, Season 4 Episode 7, "Mockingbird"}

Cersei: Highgarden bought us the most powerful army in Essos the Golden Company. 20,000 men, horses, elephants, I believe.
Jaime: The Golden Company is not here.
Cersei: They're in Essos.
Jaime: How is a mercenary company in Essos going to help us?
Cersei: Do you really think Euron Greyjoy turned tail and sailed back to the Iron Islands? Do you think he abandoned the chance to marry the queen? No one walks away from me. He's sailing with his fleet to Essos. He's going to ferry the Golden Company back here to help us win the war for Westeros.
_{Game of Thrones, Season 7 Episode 7, "The Dragon and the Wolf"}