It's a tiny detail but it's neat to see how clearly George based Aegon on William. It's not just them both being conquerers and founders of a royal dynasty, they even mirror each other in their opening moves of the Conquest.

Source for the William details is "Empires of the Normans" by Levi Roach

Aegon landed at the mouth of the Blackwater Rush. It's said that petty kings established "towers and forts" on the three hills there, but when Aegon lands only, "broken stones and overgrown ruins remained."

Aegon would build a "log-and-earth palisade" on the highest hill.