What was the one MOST important action that Julius Caesar took to change the Roman Republic? pls be specific my teacher is strict she will make me do this again

The rich lands of Gaul were a huge and valuable asset for the Empire. By stabilising the territories under imperial control and giving rights to new Romans he set the conditions for later expansion that would make Rome one of history’s great empires.

Explanation:

no, to many things have came in to factor

the government closely monitored its finances to avoid another financial collapse.