Memory palace (+ PAO?) for historical event-dates?

I’ve read her posts here in the forums. They informed some of the idea I cycled through in Historical timeline memory: my proposed system. I’ve since been convinced to not worry so much about the meta-structure (across centuries) and just get each individual century palace correct (10 rooms, with 10 locus objects each).

I just did the same thing with English/British monarchs! I went back to Egbert as well. Except, this was before I had memory palaces. So I just memorized using songs:

I really need to get away from audio-based memory