In 1954, Denis Mack Smith, who has died aged 97, produced his first book – and his masterpiece – Cavour and Garibaldi 1860: A Study in Political Conflict. Written with verve and style, it unpicks a crucial year in Italian history, undercutting a series of accepted truths concerning Italy’s unification and, in Jonathan Steinberg’s words, telling Italians “what they did not want to hear”.