Pope John VIII was the first pope to be assassinated. According to the Annals of Fulda, a history produced by a monastery in the German city, the ill-fated Pope was poisoned and then clubbed to death by his entourage. During the so-called "Iron Age of the Papacy" (867-964), powerful Roman families had popes elected and then killed according to political expediency. Seven of 26 pontiffs succumbed to vicious deaths in that era. Throughout history, 15 popes are thought to have been murdered:

John VIII (872-882): Poisoned and clubbed to death.

Adrian III (d.885): Foul play suspected because his body was never returned to Rome.

Stephen VI (d.897): Strangled.

Leo V (d.903): After 30 days in office, ousted by a priest, jailed then murdered.

John X (d.928): Suffocated with a pillow.

Stephen VII (VIII) (d.931): Believed to have been murdered.

Stephen VIII (IX) (d.942): Thrown into prison and brutally mutilated; died from his injuries.

John XII (d.964): Either died of a stroke while in bed with a mistress or was killed by her husband.

Benedict VI (d.974): Strangled by a priest on the orders of the Pope Boniface VII.

John XIV (d.984): After four months in jail, died of either starvation or poisoning.

Gregory V (d.999): Died suddenly, provoking rumors that he was poisoned; malaria is more likely.

Clement II (d. 1047): Rumors led to the opening of his tomb in 1942; tests on the remains pointed to lead poisoning.

Damasus II (d.1048): Died after 23 days in office. Although rumors of poisoning surfaced, malaria was the probable cause.

Boniface VIII (d.1303): Ill-treated while imprisoned by King Philip IV of France, he was rescued but died shortly thereafter, most likely from injuries.