But Benedict XVI's shocking resignation is even more curious when compared to the handful of others who have left the powerful office willingly. In the past 1000 years, only four other popes have resigned. Here are their unusual stories, which are also an indication of just how much the church has changed.
Pope Benedict IX, in 1045: At age 33 and about 10 years into his tumultuous term, the Rome-born pope resigned so that he could get married – and to collect some cash from his godfather, also Roman, who paid Benedict IX to step down so that he might replace him, according to British historian Reginald L. Poole's definitive and much-cited history of the 11th century.
Pope Gregory VI, in 1046: The same man who had bribed and replaced his godson ended up leaving the office himself only a year later, according to Poole's account. The trouble began when Benedict IX failed to secure the bride he'd resigned for, leading him to change his mind and return to the Vatican. Both popes remained in the city, both claiming to rule the Catholic church, for several months. That fall, the increasingly despondent clergy called on the German Emperor Henry III, of the Holy Roman Empire, to invade Rome and remove them both. When Henry III arrived, he treated Gregory VI as the rightful pope but urged him to stand before a council of fellow church leaders. The bishops urged Gregory VI to resign for bribing his way into office. Though the fresh new pope argued that he had done nothing wrong in buying the papacy, he stepped down anyway.
Pope Celestine V, in 1294: After only five months in office, the somber Sicilian pope formally decreed that popes now had the right to resign, which he immediately used. according to a report in the Guardian. He wrote, referring to himself in the third person, that he had resigned out of "the desire for humility, for a purer life, for a stainless conscience, the deficiencies of his own physical strength, his ignorance, the perverseness of the people, his longing for the tranquility of his former life." He became a hermit, but two years later was dragged out of solitude by his successor, who locked him up in an Italian castle. Celestine died 10 months later.
Pope Gregory XII, in 1415: The elderly Venetian had held the office for 10 years, but he was not the only pope. For decades, the Western Schism had left Europe with two popes, one in Rome and one in the French city of Avignon, according to Britannica. The schism's causes were political rather than theological: the pope had tremendous power over European politics, which had led its kings to become gradually more aggressive in manipulating the church's leaders. Gregory XII resigned so that a special council in Constance, which is today a German city, could excommunicate the Avignon-based pope and start fresh with a new, single leader of the Catholic church.
Pope Benedict XVI, in 2013: Citing health reasons from old age, he announced today that he will step down on Feb. 28.
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