In the early 1930s, with the rise to power of the Nazi Party in Germany with "Führer" Adolf Hitler's staunch emphasis on a Nordicist conception of the Aryan Race, strong tensions arose between the Fascists and the Nazis over racial issues, as Hitler regarded Northern Italians to be strongly Aryan, but not Southern Italians. The Nazis regarded the ancient Romans to have been largely a people of the Mediterranean race, though they claimed that the Roman ruling classes were Nordic, descended from Aryan conquerors from the North and that this Nordic Aryan minority was responsible for the rise of Roman civilization. The Nazis viewed the downfall of the Roman Empire as being the result of the deterioration of the purity of the Nordic Aryan ruling class through its intermixing with the inferior Mediterranean types that led to the empire's decay. In addition, racial intermixing in the population in general was also blamed for Rome's downfall, claiming that Italians as a whole were a hybrid of races, including black African races. Due to the darker complexion of Mediterranean peoples, Hitler regarded them as having traces of Negroid blood and therefore were not pure Aryans and inferior to those without such heritage. Hitler praised post-Roman era achievements of northern Italians such as Sandro Botticelli, Michelangelo, Dante Alighieri and Benito Mussolini. The Nazis ascribed the great achievements of post-Roman era northern Italians to the presence of Nordic racial heritage in such people who via their Nordic heritage had Germanic ancestors, such as Nazi ideologist Alfred Rosenberg recognizing Michelangelo and Leonardo da Vinci as exemplary Nordic men of history. However, the Nazis did claim that aside from biologically Nordic people that a Nordic soul could inhabit a non-Nordic body. Hitler emphasized the role of Germanic influence in Northern Italy, such as stating that the art of Northern Italy was "nothing but pure German".