Britannicus Emperor?

[Promethean]

What if instead of Nero, Brittanicus would have become Emperor?

I can see a few POD's like August lets Nero's parents (grandparents i aint sure) (or family they were enemies of Ceasar)

Agripina doesnt marries Claudius.

Claudius has more luck in his private live.

The Preatorians revolt when Nero becomes Emperor.

What effects could have another Emperor in this period have on the world or the Roman Empire?