Robert Prevost's time here as bishop also involved difficult decisions, such as having to deal with the controversy and scandal surrounding the dissolution of Sodalitium of Christian Life, a Peruvian Catholic organisation that had faced decades of sexual abuse allegations.

Santiago Roncagliolo, a Peruvian writer and journalist who has studied the Pope's life, believes his handling of that crisis earned him the favour of his predecessor, Pope Francis, and helped set him on the path to the papacy.

Father Miranda also stressed the role the now-pontiff played in bringing people together.

"If there is one thing Bishop Prevost worked for here," he added, referring to the Pope by his previous title, "it was unity".

That unity has been on display in the run up to the Mass, with the square in front of Chiclayo Cathedral filled with joyous celebrations for days.

Read More