The world’s Catholics were surprised by the news that Pope Benedict is going to resign at the end of the month.

The Pope told a meeting of cardinals that, because of his advanced age and diminishing strength, he didn’t feel he could carry on the job.

The 85-year-old has been seen using a cane at times, and recently appeared to have trouble reading the text of a speech in Rome.

Resignations by Popes are not unheard of, but Benedict will be the first in more than 500 years to step down.

He was 78 when he became Pope. That made him one of the oldest to be elected to the papacy.

A number of possible successors are being discussed, including Canada’s Marc Cardinal Ouellet.

Cardinals from around the world will gather in Rome to elect a new Pope next month.