Dagda is a vast land that remains relatively unexplored due to its remoteness. Early on, there were conflicting accounts about its environment: some claimed it was a tropical rain forest, while others contended it was a giant, frozen plateau. In reality, Dagda stretches far to the north and south, and has a diverse geography.
In Imperial Year 721, Dagda sent an army across the sea to invade the land of Mach near Fódlan, sparking the First Mach War. The Adrestian Empire drove the invasion back, but Mach suffered extensive damage in the fighting.
The Adrestian Empire embarked on a retaliatory campaign against Dagda in 728 with the Invasion of Brigid. Brigid, an ally of Dagda at the time, was forcibly subjugated, and then used as a foothold for the Invasion of Dagda in 731. However, the Empire's attempt to conquer Dagda ultimately failed.
The Dagda and Brigid War occurred in 1175. Dagda joined forces with Brigid to invade the Empire, making landfall in the territories of Nuvelle and Ochs. They caused considerable damage before they were driven out. The war claimed the life of Petra's father, the son of the king of Brigid, and resulted in Brigid being forced into vassalage to the Empire. Dagda was also left in ruins by the Imperial counter-invasion.