The RFU Championship (known for sponsorship reasons as the Greene King IPA Championship between 2013–14 and 2019–20) is the second tier of the English rugby union league system and was founded in September 1987. The twelve-side league was known as National Division One and in 2009 changed from semi-professional clubs to fully professional. The 2020 champions were Newcastle Falcons, winning automatic promotion to Premiership Rugby. Originally the league required an end-of-season round of two-legged play-offs in which the top eight, from 2012–13 until 2016–17 revised to top four, clubs at the end of the main phase of the season played each other. On 10 November 2008 it was proposed by the Rugby Football Union that the second tier of the English rugby union system should be a fully professional twelve club Championship.