Arnaldo Dante Momigliano, KBE (5 September 1908 – 1 September 1987) was an Italian historian known for his work in historiography, characterized by Donald Kagan as "the world’s leading student of the writing of history in the ancient world".
Momigliano was born on 5 September 1908 in Caraglio, Piedmont. In 1936 he became Professor of Roman history at the University of Turin, but as a Jew soon lost his position due to the anti-Jewish Racial Laws enacted by the Fascist regime in 1938, and moved to England, where he remained. After a time at Oxford University, he went to University College London, where he was Professor from 1951 to 1975. Momigliano visited regularly at the University of Chicago where he was named Alexander White Professor in the Humanities, and at the Scuola Normale Superiore di Pisa. He wrote reviews for The New York Review of Books In addition to studying the ancient Greek historians and their methods, he also took an interest in modern historians, such as Edward Gibbon, and wrote a number of studies of them.
Momigliano stressed the wasteful futility of identifying and explaining the forces held responsible for the gradual disintegration of the Roman Empire, while then redirecting his students' focus:
Historians, one must admit, were not created by God to search for causes. Any search for causes in history, if it is persistent, ...becomes comic—such is the abundance of causes discovered. ...What we want is to understand the change by analyzing it and giving due consideration to conscious decisions, deep-seated urges, and the interplay of disparate events. But we must have a mental picture, a model of the whole situation as a term of reference, and here, I submit, is where Gibbon helps us.