So I just learned that the Irish had Medieval Kings, ranging back centuries across their entire Island.

https://en.wikipedia.org/wiki/High_King_of_Ireland

https://en.wikipedia.org/wiki/O%27Brien_dynasty

https://en.wikipedia.org/wiki/King_of_Munster

https://www.obrienclan.org/first-high-king-of-the-irish.html

Neat stuff