> The murder of Caesar marked the beginning of a long and protracted civil war
I don't see how you can look at the events leading up to the murder of Julius Caesar as anything but a civil war. He literally led roman armies into battle against roman armies controlled by opposing political interests.
> The death of Caesar did not provoke the end of the Republic
The amount of political power concentrated in the single dictator-for-life changed dramatically after this. If you want to call a system in which one person has dictatorial power a republic because they will lose that dictatorial power via assassination or revolt if they are awful enough at their job for long enough (e.g. Nero) then basically anything is a republic.
I don't see how you can look at the events leading up to the murder of Julius Caesar as anything but a civil war. He literally led roman armies into battle against roman armies controlled by opposing political interests.
> The death of Caesar did not provoke the end of the Republic
The amount of political power concentrated in the single dictator-for-life changed dramatically after this. If you want to call a system in which one person has dictatorial power a republic because they will lose that dictatorial power via assassination or revolt if they are awful enough at their job for long enough (e.g. Nero) then basically anything is a republic.