The Old Empire of Ghis founded the city under the name of Gorgai. The Ghiscari held Gorgai for between two to four centuries until the Valyrian Freehold captured it during the Third Ghiscari War and renamed it Gogossos. The dragonlords used it as a penal colony for the worst criminals. New methods of torture were used and blood magic is said to have been practiced, including slave women being forced to mate with beasts to produce twisted, half-human offspring.
Gogossos grew powerful through slavery and sorcery during the Century of Blood, with some calling it the "Tenth Free City". Its slave markets became as notorious as those of the cities of Slaver's Bay. Seventy-seven years after the Doom of Valyria, however, the Red Death emerged from the slave pens of Gogossos and swept from the Isle of Tears and to the rest of the Basilisks. Nine of every ten men died from the plague.