Pope Francis has beatified John Paul I, the happy and humble pontiff known as “the smiling pope,” whose death after just 33 days as leader of the world’s Roman Catholics gave rise to decades of speculation and rumor, The Guardian reported.

At a ceremony in St Peter’s Square on Sunday, which marked the last formal step before canonization, Francis praised John Paul I’s brief but cheerful papacy.

“With a smile, Pope John Paul managed to communicate the goodness of the Lord,” he said during mass.

Born Albino Luciani on 17 October 1912, in the northern Italian town of Canale d’Agordo, John Paul I went on to become patriarch of Venice, cardinal and then the head of the Roman Catholic church.

Luciani, who took the name John Paul after being elected pope on 26 August 1978, was found dead in bed at his Vatican apartment on 28 September that year.

Although the Vatican said he died of a heart attack, it gave conflicting versions as to the circumstances in which his body was discovered.

Despite initially claiming he had been found by a priest who served as his secretary, it later acknowledged he had been found dead by one of the nuns who used to bring him his morning coffee.

Given the huge financial scandal developing at the time in Italy involving figures who had links to the Vatican’s bank, suspicions quickly took root in the secular media that John Paul had perhaps been poisoned because he intended to tackle wrongdoing.

Books speculating on the circumstances surrounding his death sold millions of copies.