The Great Jubilee in 2000 was a major event in the Roman Catholic Church, held from Christmas Eve (December 24), 1999 to Epiphany (January 6), 2001. Like other previous Jubilee years, it was a celebration of the mercy of God and forgiveness of sins. The major innovation in this Jubilee was the addition of many "particular Jubilees" for various groups of persons, and that it was simultaneously celebrated in Rome, Israel, and elsewhere in the world.
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.
The formal convocation of the holy year came through the papal bull of indiction, Incarnationis Mysterium (Mystery of the Incarnation), on November 29, 1998. In the bull, the Pope indicated that he had desired to lead the Church into the Great Jubilee since the beginning of his pontificate. He explained that this Jubilee would be a chance to open new horizons in preaching the Kingdom of God. However, it would also be a time of repentance, both for individuals and for the Church as a whole. Furthermore, he stressed the ecumenical character of this event, which he saw as not only for Catholics, but for all Christians and indeed for the whole world.
The various churches and cathedrals in Rome took advantage of the Jubilee to perform long-needed renovations. The facade of St. Peter's was under scaffolding for months, as centuries of grime were painstakingly removed. The Holy See also arranged to build a massive parking garage under the Janiculum hill, in order to accommodate all the buses that were expected. Construction of the garage was halted for some time due to the discovery of mosaics dating from the imperial period in previously unknown chambers under the hill. These were removed en masse so as to be able to complete the garage in time for the Jubilee.