Numerous finds show that the settlement at Herdla goes back to prehistoric times, and the large estate at Herdla has enjoyed a central place in the nation’s history since High Middle Ages. As Ask, Herdla was part of the country estate Harald Hårfagre took over as he took command of the west of Norway.
“At thick of night a thundering knock on the door; the man in the house wakes up, jumps out and demands: Who cries? Yes, now you must out, the beacon shines on Høgenut. And in the same breath, every man knew that strife had hit the land.”
The coastal settlement of Os begins to take form in the middle of the 1800s. This is when craftsmen and traders begin to settle at the river delta.