Factbox: What is a Roman Catholic Holy Year?
ROME(Reuters) - Roman Catholics start celebrating an extraordinary Holy Year on Dec. 8. Pope Francis has chosen the theme of mercy for one of the Church's most important events. But what exactly is a Holy Year?
A Holy Year, also known as a Jubilee, usually happens once every 25 years, unless a pope calls an extraordinary one to call attention to a particular issue or celebrate a momentous event.
The first Roman Catholic Holy Year is believed to have been instigated by Pope Boniface in 1300.
The last ordinary Holy Year was held in 2000 under Pope John Paul II. The last extraordinary Holy Year was called by John Paul II in 1983 to mark 1,950 years since the death of Jesus.
During a Jubilee, Catholics can obtain special indulgences, or remission of their sins, if they fulfill certain conditions and do good works or make pilgrimages. The Vatican website says a Holy Year should also be a time of reconciliation with adversaries and an occasion to promote solidarity, hope and justice in the world.