British and Irish Cup
The British and Irish Cup was an annual rugby union competition for second tier, semi-professional clubs and the reserves or developing teams from professional clubs from Great Britain and Ireland. It took place for the first time in the 2009–10 season, and ran for 9 seasons.
After clubs from the English Championship decided to withdraw from the 2018-19 season, the competition was abolished. The Welsh and Irish rugby unions thereafter reinstituted the Celtic Cup competition for its development sides.
Leinster A and Munster A were the most successful sides in the competition, winning the trophy twice each. Five English clubs shared the remaining competition wins.
A total of twenty-four teams from England (twelve), Ireland (three), Scotland (three) and Wales (six) competed in the inaugural competition. This remained the case for the first three seasons, though the format varied slightly in each season. For the 2012–13 season, the competition was expanded to 32 teams; England (twelve), Ireland (four), Scotland (four), and Wales (twelve) and for the first time, pool stage games were played on a "home and away" basis. For the 2013–14 season the number of teams competing was reduced to 24, with the Welsh entrants reduced from twelve to four, and the following season the competition was reduced to twenty teams with the withdrawal of the Scottish clubs.
From the 2015–16 season to its end in 2018, Wales was represented by regional Premiership Select sides from the four Welsh regions.
Wikipedia — https://en.wikipedia.org/wiki/British_and_Irish_Cup