The 85-year-old announced the decision in Latin during a meeting of Vatican cardinals this morning.
He said that because of his age and diminishing strength, he didn't feel he could carry on.
On the Island, Lord Bishop Robert Paterson has described the Pope as having a formidable intellect but also formidably conservative.
He admits the resignation has come as a surprise:
Yellow warning for coastal overtopping to come into force later
It's expected from 11am
Garff candidates put in 'terrible' position by windfarm advice says new MHK
Hewison criticises warning given by AG's chambers
Quaterbridge Road closed for tree works
Expected to re-open at 5pm
Douglas Council to hold annual Civic Service
UPDATE: Parade from City Hall CANCELLED