In the dying light of the nineteenth century, the world came to know and fear terrorism. Much like today, this was a time of progress and dread, in which breakthroughs in communications and weapons were made, political reforms were implemented and immigration waves bolstered the populations of ever-expanding cities. This era also simmered with political rage and social inequalities, which drove nationalists, nihilists, anarchists and republicans to dynamite cities and discharge pistols into the bodies of presidents, police chiefs and emperors. This wave of terrorism was seized upon by an outrage-hungry press that peddled hysteria, conspiracy theories and, sometimes, fake news in response, convincing many a reader that they were living through the end of days. Against the backdrop of this world of fear and disorder, The rise of devils chronicles the journeys of the men and women who evoked this panic and created modern terrorism – revolutionary philosophers, cult leaders, criminals and charlatans, as well as the paranoid police chiefs and unscrupulous spies who tried to thwart them. In doing so, this book explains how radicals once thought just in their causes became, as Pope Pius IX denounced them, little more than ‘devils risen up from Hell’.