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:
Survey finds half of businesses expect to make cutbacks or redundancies in 2026
Figures compiled following recent minimum wage meeting
Braddan Commissioners appeals for information after tyres fly-tipped on Marine Drive
Local Authority says it's a criminal offence and will be investigating the incident
Allinson: Government responding to calls over MiCard system
Previous plans to discontinue service have come under fire this week
Mountain Road closure extended by additional 24 hours
The road has been closed since Wednesday
Number of primary school pupils choosing school meals down nearly 20%
Data throughout the year shows more students taking up packed lunch