Guglielmo Ferrero (gōōlyĕl´mō fār-rĕ´rō), 1871–1942, Italian man of letters and historian. With his father-in-law, the criminologist Cesare Lombroso, he collaborated in the writing of La donna delinquente (1893, tr. The Female Offender, 1895). His interest in psychology and sociology permeates his writings. An outspoken critic of Fascism, Ferrero was exiled by Benito Mussolini and became (1930) professor of history at the Univ. of Geneva, Switzerland, where he died. Among his numerous works the best-known deal with Roman history, notably The Greatness and Decline of Rome (5 vol., 1902–7, tr. 1907–9).