The Commodore was Nucky Thomson's mentor and helped build Atlantic City, using corrupt means to do so. and teaching Nucky the finer points of leveraging politicians, money and favors to run an entire city. Through an agreement between them, the Commodore retired and Nucky was left to control the operation. Still, he doesn't seem content to stay in retirement very long, demonstrating some resentment toward Nucky for the lavish lifestyle he leads as the man in charge -- all of which the Commodore once had for himself.