From things for which Roman Catholic popes have apologized.

Colonialism
Complicity in the slave trade
Passivity during the Holocaust
The Inquisition
Systemic sexual abuse
Missionaries in China
Sins against the Roma
Sins against Aboriginal peoples
Sins against the Jewish people
Sins against Irish women and children
Repeating quotes that the Prophet Mohammed was “evil and inhuman”
The theft of indigenous Amazonian statues
Sacking Constantinople
Mistreating Galileo
Preventing women from being themselves
Slapping a woman’s hand
Forcing a future pope to kneel
Attending an orgy
Being the pope