ESPN celebrates the 100th anniversary of Vince Lombardi's birth with the "Greatest Coaches in NFL History" series, saluting the finest innovators, motivators, tacticians, teachers and champions ever to stalk the sidelines. Follow along as we reveal our list of the top 20 coaches of all time and document the lineage of the league's most influential coaching trees.

The George Halas coaching tree is documented in the chart below, followed by a feature on Halas and short biographies of his many disciples.

This package also includes a feature on the George Allen branch of Halas' tree.