The Aviva Premiership is the top professional rugby union league in England, featuring twelve teams that compete annually. Established in 1997, it showcases some of the best talent in the sport and operates on a promotion and relegation system with the RFU Championship. Matches typically run from September to May, culminating in a playoff system that determines the champion. The league is known for its competitive nature and has produced many notable players and clubs, contributing significantly to the growth of rugby in England and beyond.