Complex sentence: Following the March on Rome in October 1922 he became the 27th Prime Minister of Italy and began using the title "Il Duce" by 1925, within five years he had established dictatorial authority by both legal and extraordinary means, aspiring to create a totalitarian state.
Split into simpler sentences: Following the March on Rome in October 1922 he became the 27th Prime Minister of Italy. Within five years he had established dictatorial authority by both legal and extraordinary means, aspiring to create a totalitarian state.