There is a great article by Gavriel D. Rosenfeld called "Who Was “Hitler” Before Hitler? Historical Analogies and the Struggle to Understand Nazism, 1930–1945".

In the article, he shows that "[t]here was no “Hitler” before Hitler. There was no single figure denoting evil in the same uncontested way that the former Führer does today. The world before Hitler was one in which evil was plural rather than singular."

Counting examples from the English-speaking world, Germany, and some other countries mostly based on Günter Scholdt's book Autoren über Hitler: Deutschsprachige Schriftsteller 1919-1945 und ihr Bild vom ‘Führer’ (1993) , gives the following examples: "1) ancient tyrants and conquerors, such as the pharaohs of Egypt, King Nebuchadnezzar II of Babylon, Haman of Persia, the Seleucid King Antiochus IV, King Herod of Judea, Julius Caesar, Emperor Nero, Philip of Macedon, and Alexander the Great; 2) “barbarian” warlords, including Hannibal of Carthage, Attila the Hun, Genghis Khan, Alaric the Visigoth, and Genseric the Vandal; 3) medieval and early modern religious fanatics, such as Girolamo Savonarola, Tomás de Torquemada, Jan Bockelson, Henry VIII, and the French Catholic perpetrators of the St. Bartholomew's Day massacre; 4) modern dictators, either actual or aspiring, such as Oliver Cromwell, Maximilian Robespierre, Napoleon Bonaparte, Napoleon III, and Georges Boulanger; 5) mythical figures drawn from different religious and cultural traditions, including Christian theology (Satan), Greek mythology (Icarus, Sciron), and Nordic lore (Wotan, Loki)."