There is a very long history of apocalyptic thinking in the history of Christianity, and one particularly strident episode came in the wake of the Protestant Reformation — specifically with regards to Martin Luther, who truly believed the End Times were imminent. Interpreted through Luther’s lens of European religious trends in the early 16th century, this meant that the Catholic Pope was an agent of the Devil, and was the Antichrist from the _Book of Revelation_.
Here you see a famous woodcut by Luther’s friend Lucas Cranach that appears in his pamphlet _Passional Christi und Antichrist_. It was incredibly popular in Europe, particularly in German-speaking countries, and had a major impact on Protestant thought. On the right panel, Jesus washes and kisses the feet of the poor, while on the left, the inversion happens, in which the Pope recieves obeisance as a servant anoints his feet.
Many Protestants thought of Martin Luther as a divinely-sent prophet of the Last Days, comparing him to a second Elijah. One thinker called Michael Stifel, even went so far as to equate Luther with the Biblical angel from Revelation 14:6: “Then I saw another angel flying in midheaven, with an eternal gospel to proclaim to those who dwell on earth, to every nation and tribe and tongue and people; and he said with a loud voice, ‘Fear God and give him glory, for the hour of his judgement has come . . .”
Stifel was wrong of course, as was Luther, about the End Times. The popularity of reading the _Book of Revelation_ as a prophetic testament to the Last Days has continued, since it is always easy to read all the signs of doom however one wants. And it’s equally easy to assign the Antichrist label to whomever one really detests.
Sources: _The Four Horsemen of the Apocalypse: Religion, War, Famine and Death in Reformation Europe_, Andrew Cunningham and Ole Peter Grell, Cambridge UP, 2000, pp 26-28.