The event started in 1934 and is now played over one weekend for Womens teams from England, Scotland, Wales, Northern Ireland and the Republic of Ireland. Since 2009 the host fields a sixth team called by the name of the Federation (CBAI). This team can also win the trophy for the country and did so for England in 2010. Teams play a head-to-head match of 32 boards against each of the other five, each being victory-pointed. In 2011 for the first time in 62 years the series ended in a tie, the trophy being shared between Scotland and England. The regulations for a tie were subsequently changed making one a lot less likely.
England has won outright on 48 occasions (one being its second team in 2010). Scotland has won outright 14 times: in 1950, 1956, 1980, 1984, 1986, 1992, 1994, 2004, 2007, 2009, 2012, 2014, 2016 & 2018; Wales won in 1967, 1968, 1988 and 2015 Northern Ireland won in 1981 and 1985; the Republic of Ireland, joining the series in 1998, has yet to win.