As was said earlier, it's fair to assume that most people have some Allagan ancestry in their history due to the fact that the Allagan Empire spanned the entire known world, with the exception of parts of southern Meracydia. However, the Empire was all but wiped out during the 4th Umbral Calamity 5000 years ago. Those Allagans and Meracydians who survived went on to repopulate the 4th Astral Era civilizations.
However, over the course of 5,000 years, most knowledge of the Allagans was lost and their existence became a myth until a historian named Saint Coinach proved the Allagans existed. A lot of the myths surrounding Allag are the basis for the Lambs of Dalamud cult, who believe they are directly descendant from the Allagans.
A few other notable NPCs claim a direct line to ancient Allag, including VIIth Legatus Nael van Darnus and G'raha Tia from the CT storyline.
However, over the course of 5,000 years, most knowledge of the Allagans was lost and their existence became a myth until a historian named Saint Coinach proved the Allagans existed. A lot of the myths surrounding Allag are the basis for the Lambs of Dalamud cult, who believe they are directly descendant from the Allagans.
A few other notable NPCs claim a direct line to ancient Allag, including VIIth Legatus Nael van Darnus and G'raha Tia from the CT storyline.