Many of the men who have been chosen for the highest office didn't get a chance to do much with it. Pope-elect Stephen was elected in A.D. 752, but died just a few days later, without being consecrated into office. Pope Damasus II ascended to the papacy in 1048, after several political squabbles, but passed away just 23 days later. Celestine IV, who was elected in 1241, died just 16 days later - too early for his coronation. And Pope Urban VII, at 12 days in A.D. 1590, was the shortest-reigning pope in the Catholic Church's history.
The Catholic Church has also had several periods where no pope reigned. These gaps, known as interregnums, usually occurred when the cardinals who vote for the pope were deadlocked.