Greg Diefenbach is the Vice President of Program Development for Devillier Donegan Enterprises, a Disney/ABC subsidiary specializing in the development and distribution of high-quality, non-fiction television. Diefenbach supervises the development and production of some 30 hours of prime-time programming annually for DDE, including the "EMPIRES" series on PBS.

Prior to joining DDE, Mr. Diefenbachworked for the National Geographic Society's weekly documentary series, Explorer. In his nine years with National Geographic -- over a span of more than 40 productions -- he served in a variety of roles, including producer, director, researcher and writer.