Preparation for the Great Jubilee began when Pope John Paul II issued his Apostolic Letter Tertio Millennio Adveniente (As the Third Millennium Approaches) on November 10, 1994. In the letter, he invited the Church to begin a three-year period of intensive preparation for the celebration of the third Christian millennium. The first year, 1997 would be marked by an exploration of the person of Jesus, the second, 1998, by meditation on the person of the Holy Spirit, and the third, 1999, by meditation on the person of God the Father. Each year was also to be marked by a special prayer of entrustment to the Blessed Virgin Mary.