King Kennon Harrigon I in an unseen character in Game of Thrones, having been dead centuries before the beginning of the series. He was King of the Forges and the head of House Harrigon during Aegon's Conquest of Westeros. He bent the knee to both Orys Baratheon and Aegon Targaryen, becoming the first lord of Smithestone as the Kingdom of the Forges fell.
King Kennon was known as one of the strongest Steel and Silver kings, having held off attacks from King Argilac Durrandon for many years. After hearing of the defeat of King Argilac by Orys Baratheon, he stopped all forging and shipments until he could face Orys on the field. This was until Aegon arrived with Balerion the Black Dread. Aegon destroyed the Smithe Gate, burning many of his soldiers and blacksmiths to death. To end the rampage and secure the future of Hornworth's forges, King Kennon bent the knee to Aegon. When a part of Aegon's army arrived, he inspected the forges inside Hornworth, and proclaimed Kennon Lord of Hornworth and Lord Defender of Steel and Silver. Before he left, he brought a large amount of Valyrian Steel into the forges, which enabled House Harrigon to finally rid themselves of debt they owed to many noble families and even the Iron Bank.
For the rest of his life Kennon was known as the "King who Forged", losing his title of King and become the lord Blacksmith his descendants would be left as.