Following the First World War, Europe and the US suffered a breakdown as nations. Behaviour was non-Christian, atheism flourished. Thus, the Feast was established on the last Sunday of October to turn things around. An encyclical accompanied the new feast day which was to be read after Mass on this day: The Act of Consecration of the Human Race to the Sacred Heart of Jesus. The beautiful Introit takes us into the very realm of Heaven where our King reigns. He is the Lamb that was slain.
The Collect carries forth the sentiment that the Eternal Son is King of the whole world. St. Paul’s powerful Epistle tells us plainly that He is the head of the body of the Church, who is the beginning, the first born from the dead, that in all things, He may hold the primacy. He will rule from sea to sea (Gradual), and His Kingdom a kingdom that shall not decay (Alleluia).
Jesus Himself told Pilate Thou sayest that I am a King. For this was I born, and for this came I into the world (Gospel). Our King is immolated on the altar that He may Himself give to all nations the gifts of unity and peace (Secret). The Communion and Postcommunion tell us that our King will bless His people through the Food of immortality which was just received.