The Explorers' Club, № MCXXVIII

Operation AXIOM: Between the Wars
11 December 1925: Pope Pius XI promulgated the encyclical Quas primas ("From the first…") in response to the Great War & the global wave of revolutions (1917-1923), reminding a secularizing world that true peace is only possible when Christ reigns as King in the hearts of men; the Feast of Christ the King was added to the Church calendar from 1926 & adopted by many Protestant groups.

Commentary: From 1926-1969, the Feast of Our Lord Jesus Christ the King was celebrated on the last Sunday before All Saints' Day (the last Sunday in October); since 1970, the Solemnity of Our Lord Jesus Christ, King of the Universe is celebrated on the last Sunday before the First Sunday in Advent (the last or second-to-last Sunday in November).

Lest we forget.