In the wake of Pope Benedict's decision to resign from the papacy, journalists quickly recalled that Pope John Paul II had also prepared letters of resignation to take effect in the event that he lost his capacity to continue as leader of the church.
But those two are not the only modern popes who prepared to resign.
In the 1940s, Pope Pius XII wrote a letter of resignation that would take effect immediately if Adolf Hitler ever had him arrested, according to a Jan. 28, 1988, report by John Thavis of Catholic News Service (then National Catholic News Service).
Here, from the CNS archives, is that 1988 story:
PIUS XII PREPARED TO RESIGN IF ARRESTED BY NAZIS, SAYS OFFICIAL
By John Thavis
VATICAN CITY -- Pope Pius XII planned to resign to avoid a crisis of church leadership in case Adolf Hitler made good a plan to arrest the pontiff and remove him from the Vatican, a top Vatican official said.
"If he were arrested and conducted beyond the walls of Rome, he would have been immediately considered to have given up the throne of Peter,'' said Cardinal Pietro Palazzini. Thus "the prisoner would be Eugenio Pacelli (his baptismal name) and not the pope,'' he said.
The cardinal said Pope Pius left the written resignation with a Vatican lay official.
Cardinal Palazzini said the pope was aware of a plan by Hitler to arrest him. He said the pope was afraid of putting the church in a crisis similar to that of the late 18th century, when Pope Pius VI was seized by French forces and the church had to await his death in captivity before restoring church government.
Cardinal Palazzini commented on the papal plan in an interview in the February issue of the Italian magazine, Trenta Giorni (30 Days). The magazine made excerpts from the interview available in advance of publication. A spokesman for the cardinal confirmed the remarks.
Cardinal Palazzini, 75, is prefect of the Congregation for Sainthood Causes. During World War II, he helped political refugees as an official at Rome's major seminary, according to a Vatican biography.
Pope Pius' conduct during the war has long been a subject of controversy. Some commentators said the pontiff could have spoken out against the Nazi persecution of Jews, but elected to remain silent.
Defenders say the pope quietly did what he could to help Jews, and early in the war relayed a message to the British from a group of German generals who sought to depose Hitler.
A key to Pope Pius' public silence about Nazi atrocities was Hitler's campaign to crush the German Catholic Church, along with his other opponents, a Vatican historian has said. The pope feared public criticism would accelerate the dictator's effort, the historian said.