The founder of paradis island king Fritz used a power only true blood kings could use the power to shapshift into a titan he commanded his followers to use there hardening abilities to create the very walls we live behind.
But the people who live behind these walls today have known idea why we live like this because everyone who did has either been killed by a titan or silences by someone who thought they knew to much.
The only people left who know our true origin are the very people who saw king Fritz leave and his blood line
Because since king Fritz was the founding Titan he could protect his memorys into the most recent king or queen who is ruling the kingdom at the time. At present the king or our city is a fake he killed the previous king and sold his only hair into slavery or so he thought.
I am also a ansester of king Fritz and I was sent into hiding so I don't meet the same date as my sister historyia. Only us two are the only ones left of the true royal bloodline.