Pope Francis marks 10 years as head of the Roman Catholic Church on Monday celebrating Mass with cardinals in the chapel of the Vatican's Santa Marta hotel where he has lived since his election.
The Argentina-born Francis, 86, became the first Latin American pontiff on March 13, 2013, succeeding Benedict XVI who had become the first pope in six centuries to resign.
"It seems like yesterday," he said in a podcast by Vatican News broadcast on Monday. "Time flies. When you gather up today, it is already tomorrow."
When it was recorded at his residence on Sunday, he asked: "What's a podcast?" according to Vatican News reporter Salvatore Cernuzio. When it was explained to him, he said "Nice. Let's do it".
The former Cardinal Jorge Mario Bergoglio has sought to project simplicity into the grand role and never took possession of the papal apartments in the Apostolic Palace used by his predecessors, saying he preferred to live in a community setting for his "psychological health".
He has invited all the cardinals who are in Rome with him to the Mass on Monday.
A persistent knee ailment has forced Francis to alternate between a cane and a wheelchair but he appears to be in good overall health.
"You don't run the Church with a knee but with a head," he reportedly told an aide after he began occasionally using a wheelchair in public for the first time last May.
Francis has said he would be ready to step down if severe health problems prohibited him from running the 1.38-billion-member Church. But he has also said he thinks popes should try to reign for life and that being emeritus pope - as Benedict was - should not become a "fashion". Benedict resigned on health grounds but lived nearly 10 more years.
With his 10 years as pontiff, Francis has now reigned longer than the 7.5 years average length of the previous 265 pontificates. He has visited 60 states and territories, clocking up almost 410,000 km (255,000 miles).
But he has not returned to his native Argentina, an absence that has prompted much speculation.
He has named about 64% of the so-called cardinal electors who are under 80 and thus eligible to enter a conclave to elect his successor after he dies or resigns.
Francis marks the anniversary having outlasted conservative opposition within the Church that has several times demanded his resignation and which is now at a crossroads, seeking new direction following the deaths of two of its leading figures.
The longest papacy is believed to be that of St. Peter the apostle, the first pope, estimated to have lasted about 35 years.
The longest papacy in recent centuries was that of Pius IX, which lasted more than 31 years between 1846 and 1878. After that comes the papacy of John Paul II, who reigned for more than 26 years between 1978 and 2005.
The shortest is believed to be that of Urban VII, which lasted 13 days in 1590.