Pope John Paul I died suddenly on September 28, 1978, only 33 days after his election as pope. The official cause of death was a heart attack (acute coronary thrombosis), which likely occurred the night before he was found dead in his bed with the reading light still on and a book in his hands

. He had complained of chest pains hours before his death but declined to have a doctor called

. His death shocked the world and led to widespread mourning in several countries

. Despite his very brief pontificate, he was known for his humility, kindness, and efforts to reform the Church

. There have been numerous conspiracy theories and speculations about the circumstances of his death due to the suddenness and some inconsistencies in initial reports, but investigations and testimonies, including those published in 2017, support the conclusion that he died of natural causes—a heart attack

. Pope John Paul I was beatified in 2022, a step toward sainthood, after a miracle was attributed to his intercession