Pope Francis talks with bishops during the Liturgical Week at the Vatican in August 2017.
AP Photo/Domenico Stinellis
At stake here is the language used for the Mass and the question of who has the responsibility for translating the Catholic liturgy into regional languages.
So why should this issue be so very controversial in the 21st century?
As a specialist in liturgical studies, I can say that, until the end of the 10th century, local bishops indeed made their own decisions about