See my post, The Differences Between the Feast of Christ the King and the NO 'Solemnity of Christ the King', for the way Paul VI destroyed this feast.
CHRIST THE KING. A feast originally established by Pope Pius XI in 1925, to be celebrated with special solemnity on the last Sunday of October. It is now observed on the last Sunday of the liturgical year. Its object is to worship Christ's Lordship of the Universe, both as God and Man, and it was instituted to meet the crisis of faith in the Savior's authority, exercised by the Church, of which he is the invisible head.