Pope Pius XI, wanted to crown the jubilee year of 1925 by the institution by the introduction of a new feast to honor the kingship of Christ, instituted the Feast of Christ the King (Festum Domini nostri Jesu Christi regis) with his encyclical Quas primas of 1925, in response to growing secularism and secular ultra-nationalism
This is a rotating Feast Day, the date was established as the last Sunday of the month of October, which id the Sunday, that immediately precedes the Feast of All Saints.