As Doctor Who celebrates its 50th anniversary in November, many have wondered why this show has survived when so many others have been cancelled, drifted into obscurity and/or forgotten. One of the reasons often cited, is the concept of regeneration as a means of filling the role of the Doctor when the lead actor leaves the show. While other programs might have hired a replacement who looked or acted like his predecessor the choice to select 11 different actors with 11 different interpretations of the role is unique to Doctor Who. When William Hartnell stepped aside, he is said to have named Patrick Troughton as the only man who could replace him in the iconic role of The Doctor. With no internet and organized fandom to speak of, viewers must have been mystified by the change and perhaps wondered when "their" Doctor would return. Soon they would grow to love the 2nd Doctor and te rest was history. Part of Doctor Whos outstanding longevity has to be attributed to the man who assumed the role after William Hartnells health forced him to walk away from Doctor Who in 1966. Today, we take a look at the Patrick Troughton era of Doctor Who and why the 2nd Doctor may be the greatest Doctor of them all!