This cartoon by Nick Anderson from the Houston Chronicle relates to the resignation of Pope Benedict XVI. A TV reporter is shown outside St. Peter's Basilica in the Vatican. She informs the viewers that Benedict XVI is the first Pope to resign since the Dark Ages, adding that this was "the last time the church updated its views on female priests, contraception and homosexuality ..."
The Dark Ages are a period of European history between about 500 A.D. and about 1000 A.D. In fact, the last Pope to resign was Pope Gregory XII in 1415, which is some time after the end of the Dark Ages.
The cartoonist is highlighting the extent to which the Catholic Church is resistant to change, and seems to be stuck in the past.