‘Little children, it is the last time: and as ye have heard that antichrist shall come, even now are there many antichrists; whereby we know that it is the last time’ (1 John ii.18, KJV). That one sentence – one of only three references to the AntiChrist in the Bible, and none in the book of Revelation – set off a centuries-long quest to identify this human embodiment of evil who would set the apocalypse in motion. In this fascinating biography, Philip Almond surveys with lucidity and humour 2,000 years of Christian thinking on the AntiChrist, an imagined being that has had a profound impact on the course of Western culture. As seen in Almond's earlier biography of Satan, belief in such creatures inspired hurtful action against opponents, dissidents or minority groups, such as Jews. While Almond's biography focuses on the idea, rather than the impact, it reveals how and why Christians developed this strange idea.

They were responding to the problem of the existence of evil in a providential cosmos. Early Christians had expected a quick resolution when Jesus returned for judgement, destroying the human agents of evil, the AntiChrist and his beasts, and permanently banishing the fallen angels and sinners to hell. Yet, by 200 ce, that highly anticipated event had not transpired, so theologians were compelled to read scripture prophecy more closely, especially the books of Daniel and Revelation, to explain the unexpected passage of time. They began portraying the presence of evil in the world as part of a cosmic battle between Christ and the Devil, led on earth by the AntiChrist, that would be settled at the end of time. Evil's existence therefore did not challenge belief in a loving god, since it was only temporary.

To condense Almond's impressive survey of 2,000 years of apocalyptical interpretation into a short review cannot do justice to his incredibly detailed analysis of the first 1,200 years of Christian interpretation when the AntiChrist took shape. Almond discerns two major schools of thought: the first, fully delineated by the Benedictine monk Adso of Montier-en-Der (d. 992), depicted the AntiChrist as a tyrant external to the Church who would come in the future to deceive the world and set off the apocalypse. The second, put into final form by the twelfth-century Italian Cistercian Joachim of Fiore (c. 1135–1202), depicted the AntiChrist instead as internal to the Church, as a deceiver pope. Over subsequent centuries these AntiChrists sometimes opposed each other, and at other times interwove in intriguing ways. Some included a last world emperor who would be involved in the reform of the Church and the defeat of the AntiChrist; others had angelic popes instead. The internal AntiChrist proved a popular rhetorical tool for Catholics, such as the Spiritual Franciscans, unhappy with the church hierarchy. In the sixteenth-century Reformation, Joachim's version ruled the day, as most Protestants identified the papacy as the AntiChrist, a posture that continues to infect certain Protestant quarters to this day.

This internal AntiChrist, however, did not offer the same kind of excitement of discovery as did the external AntiChrist, who often included historical figures from the Roman emperors Antiochus Epiphanes and Nero to the Prophet Muhammed, and to modern-day political figures, such as Mussolini, or even American presidents. The time spent on calculating the eschatological timeline from ambiguous biblical prophecies – such as the forty-two months mentioned in Revelation xiii and Daniel vii, or the identity of the Beast from his numerical name, 666 – was incredible; even the great English scientist Sir Isaac Newton was obsessed with these formulae.

Along with these two major schools of thought, Almond identifies a third, one that was much less common: the spiritual AntiChrist, ‘already present within each individual’ (p. 3). While an option of early Christian Fathers, especially Origen of Alexandria (c. 185–c. 254), this position did not, at least in Almond's telling, become dominant until the nineteenth century. He does mention its revival around 1200 by the University of Paris scholar Almaric of Bena and his followers who taught that ‘god was in all things, that hell was ignorance, that heaven was only in the here and now, and that the truly “spiritual” man cannot sin’ (p. 165). They emphasised an interior faith, one in which the Holy Spirit, active in Joachim's final spiritual age, worked directly through humans, making external sacramental observance obsolete.

In such a broad sweeping overview, there will be plenty of underexplored moments, and the revival of this spiritual AntiChrist in the sixteenth century is one of these. Almond scarcely notes this in his brief overview of the Reformation, during which all sides believed and acted as if they were living in the apocalyptical moment. Most readers will be aware of the Anabaptists who sought to establish the kingdom of God in Münster in 1533–5, expecting Christ's imminent return to destroy the AntiChrist, which they saw as their governmental persecutors. With the failure of such prophecies, most remaining Dutch Anabaptists and Mennonites turned away from eschatological speculation. Some followed the former Anabaptist prophet David Joris who, returning to Origen's spiritualism, internalised eschatological events to the inner conscience, just as Joris did to angels and demons. For this he became one of the most infamous heretics of his day, even if often neglected in surveys like Almond's. One of Joris's supporters, in fact, the Reformed preacher of Gouda, Herman Herbertsz, published in 1584 a treatise decrying the Protestant identification of the pope as the AntiChrist, arguing instead that each person is instead an AntiChrist when ruled by the flesh. These Spiritualists condemned demonising rhetoric as contrary to Christ's message of love and as a root cause of religious bloodshed. This approach spread widely across the continent and England, shaping discourse related to the supernatural into the Enlightenment era.

That said, Almond's intellectual biography makes comprehensible for the modern reader the complex and obscure world of prophetic scripture interpretation, and that is a massive accomplishment.