Pope Pius XI instituted The Feast of Christ the King in 1925, to be celebrated throughout the universal church, in his encyclical Quas Primas. He connected the increasing denial of Christ as king to the rise of secularism throughout much of Europe. At the time of Quas Primas, many Christians (including Catholics) began to doubt Christ’s authority and existence, as well as the Church’s power to continue Christ’s authority.
Pius XI, and the rest of the Christian world, witnessed the rise of non-Christian (or nominally Christian) dictatorships throughout Europe, and saw Catholics being persuaded by these earthly leaders. These dictators also often attempted to assert authority over the Church. Just as the Feast of Corpus Christi was instituted when devotion to the Eucharist was at a low point, the Feast of Christ the King was instituted during a time when respect for Christ and the Church was waning, when the feast was needed most.