Pope Francis simply tweeted "Please pray for me" on his first anniversary as pontiff.
Jorge Mario Bergoglio, the archbishop of Buenos Aires, became the church's first Latin American and Jesuit leader in 2013. His name choice was also a first for a pope.
As Rome celebrates, USA TODAY Network lists five memorable moments from Francis' first year.
1. Francis washed and kissed the feet of a dozen inmates on March 28, 2013, at a detention center in Rome.
Francis celebrated this ritual for years as archbishop and continued as pope.
The fact that two of the 12 were young women was an unusual, remarkable choice given that the rite re-enacts Jesus' washing the feet of his male disciples at his Last Supper.
2. Francis said he won't "judge" gay priests, opening up a more welcoming attitude toward gay members of the church. The comments on July 29 mark the first time a pope has spoken so openly about the topic. "If someone is gay and he searches for the Lord and has good will, who am I to judge," the pope said, speaking to reporters on an overnight flight from Brazil.
BIOGRAPHY: Key facts about Pope Francis
3. Francis said on Sept. 30 that Pope John Paul II and Pope John XXIII would be declared saints April 27, the first time two former popes will have been canonized the same day and making John Paul's path to sainthood the shortest ever. Francis' declaration in July that he would canonize them together was one of the first high-profile acts of his papacy.
4. On Jan. 12, Francis announced his choice of 19 Catholic leaders to be elevated as cardinals. He chose men from around the world, including the developing nations of Haiti and Burkina, focusing on his belief that the church must pay more attention to the poor. Sixteen of the appointees are younger than 80, which means they would be eligible to elect the next pope.
5. Francis said in a wide-ranging interview with Italian newspaper Corriere della Sera in early March that marriage can only be between a man and a woman, but the Roman Catholic Church could tolerate some types of same-sex civil unions. He said that civil unions protect property rights and health care access.
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