The passing of Pope John Paul II has led to an analysis of his place in history.  As the third longest-reigning pontiff, he held the office for a little over 26 years. 

The EWTN / Global Catholic Network offers a list of the longest-serving pontiffs, as well as other information on papal topics on their See of Peter web page.   

For a definition of the Holy See, refer to the Catholic Encyclopedia, the 1913 15-volume reference book whose entries were volunteer-compiled by contributors all over the world in the late 1990s.