Aegon's forces lands at the mouth of the Blackwater Bay as he erects a crude castle out of wood and dirt called the Aegonfort. The Kings of the Seven Kingdoms of Westeros discuss on how to deal with this new enemy. However, they had no answer for Aegon's dragons. One by one, they will all succumb to Aegon's might, save for Dorne, who, through guerrilla warfare tactics, would survive the onslaught of the Targaryen armies and keep their independence. Still, Aegon would mostly succeed in his quest to unite the continent of Westeros and henceforth be known as Aegon the Conqueror.  

The first chapter is called Aegon’s Conquest. And it details the start of the Targaryen Dynasty in Westeros which began with Aegon Targaryen who would eventually unite the realm. Aegon is so crucial to the entire Game of Thrones world, that, the dating system used in Westeros was divided into BC and AC which starts for “before conquest” and “after conquest”.