PREM Rugby, officially known as Gallagher PREM Rugby, or the Gallagher PREM for sponsorship reasons and formerly known as Premiership Rugby, is an English professional rugby union competition, consisting of 10 clubs, and is the top division of the English rugby union system. From 2000 to 2025, the competition title was "Premiership". Before then it was known as "Premiership 1" and "National Division One"