Jubilee tradition dates back to the Old Testament times
Jubilee years can be traced back to a tradition described in the Old Testament where slaves and prisoners would be freed once every 50 years, a concept that died out within Judaism but was taken up by Pope Boniface VIII for the Catholic Church in 1300.
Pilgrimages to Rome were at the heart of the original jubilee years, and attracted hundreds of thousands of pilgrims to the city, many willing to pay for 'indulgences' - the eradication by the Church of the spiritual debt arising from sin.
It was a tradition that not only contributed copious cash to the Vatican's coffers, but also contributed to the theological turmoil that led to the establishment of rival Protestant churches across much of northern Europe.
The last Jubilee was called by St John Paul II to mark the millennium, and this Holy Year of Mercy starts on the Feast of the Immaculate Conception yesterday and will end on the Feast of Christ the King on November 20, 2016.