Caesar’s death official marks the end of ?

Hello Mate,
I'm not exactly sure what you're asking by saying "Caesar's death official marks the end of?" because there are a number of things that Caesar's death marks the official end of... However, I'll try and help you out as best I can.
Julius Caesar died March 15th, 44 B.C.  The biggest thing that ended after his assasentation was that the Roman Republic Ended.  However Caesar left behind him a legacy that people still talk about today, and historians still study.

Ongoing civil wars western roman empire finally collapsed476 c.e. romulus, the last of theroman  emperors in  the west, was overthrown by the germanic leader odoacer, who became the first barbarian to rule in rome. the order that the  roman empire  had brought towestern  europe for 1000 years was no more.

My opinion is that it doesn't