(Latin: "holy year")
In the traditions of the Roman Catholic Church, a special festive occasion, held every 25 years. This tradition originates in the old Israelite custom of sanctifying every 50th year as a jubilee., and in the words of Jesus Christ, according to the Gospel of Luke1.
The Catholic custom was introduced by Pope Boniface VIII in 1300. Since 1475, the annus sanctus has been held every 25 years. In a holy year, pilgrims flock to the holy places in Rome (the seven churches of pilgrimage), and participate in religious events all over the city. A door in St. Peter's Church, normally covered by a brick wall, is opened for this occasion, only to be bricked shut afterwards.2
Besides the ordinary holy years, extraordinary occasions are also marked. In 1983, an annus sanctus was held to commemorate the 1950th anniversary of the Crucifixion and Resurrection of Christ.
1 Luke, 4:17-21:
And there was delivered unto Him the book of the prophet Isaiah. And when He had opened the book, He found the place where it was written:
"The Spirit of the Lord is upon Me, because He hath anointed Me to preach the Gospel to the poor. He hath sent Me to heal the brokenhearted, to preach deliverance to the captives, and recovering of sight to the blind, to set at liberty them that are bruised,
to preach the acceptable year of the Lord."
And He closed the book, and He gave it again to the minister and sat down. And the eyes of all those who were in the synagogue were fastened on Him.
And He began to say unto them, "This day is this Scripture fulfilled in your ears."
2 Originally, this ceremony applied only to the Lateran basilica, where one of the five doors was bricked shut. The wall obstructing the door was only torn down on Christmas at the beginning of the annus sanctus, and rebuilt at the end of the year. The ritual may go back as far as the annus sanctus of 1350. A Florentine merchant, writing in the 15th century, speaks of the five doors of the Lateran basilica,
one of which is always walled up except during the Jubilee year, when it is broken down at Christmas when the Jubilee commences. The devotion which the populace has for the bricks and mortar of which it is composed is such that at the unwalling, the fragments are immediately carried off by the crowd, and the foreigners take them home as so many sacred relics. . . . Out of devotion every one who gains the indulgence passes through that door, which is walled up again as soon as the Jubilee is ended.
The ritual of the holy doors expanded to include the other major basilicas of Rome, but today the door in St. Peter's is considered most significant. The opening of this door is attended by the Pope, who carries out a ritual involving striking the door with a silver hammer, singing the versicle Open unto me the gates of justice" thrice, whereupon the masonry is made to fall.