Century 21 Affiliated is a privately held real estate brokerage headquartered in Madison, Wisconsin. Founded in 1978 by Bill Kessler, the company began as Century 21 A-K Realty and grew through mergers and acquisitions to become the largest Century 21 franchise globally. Century 21 Affiliated provides residential, commercial, and relocation services across multiple states, including Wisconsin, Illinois, Michigan, Minnesota, and California. The firm has consistently ranked as the #1 Century 21 franchise worldwide for over a decade, recognized for transaction volume and agent productivity. With a network of independently owned offices, the company emphasizes agent training, technology integration, and community engagement. Century 21 Affiliated operates under the Century 21 Real Estate LLC system, a subsidiary of Anywhere Real Estate.