Covid and security fears have made this his riskiest visit yet, but the 84-year-old insisted he was “duty bound”.
He will try to reassure the dwindling Christian community and foster inter-religious dialogue – meeting Iraq’s most revered Shia Muslim cleric.
The Pope will also celebrate Mass at a stadium in Irbil in the north.
About 10,000 Iraqi Security Forces personnel are being deployed to protect the Pope, while round-the-clock curfews are also being imposed to limit the spread of Covid.