The Rugby World Cup is a men's rugby union tournament contested every four years between the top international teams. The tournament was first held in 1987, when the tournament was co-hosted by New Zealand and Australia. New Zealand are the current champions, having defeated Australia in the final of the 2015 tournament in England.
The winners are awarded the William Webb Ellis Cup, named after William Webb Ellis, the Rugby School pupil who — according to a popular legend — invented rugby by picking up the ball during a football game. Four countries have won the trophy; New Zealand have won it three times, two teams have won twice, Australia and South Africa, while England have won it once.
The tournament is administered by World Rugby, the sport's international governing body. Sixteen teams were invited to participate in the inaugural tournament in 1987, however since 1999 twenty teams have taken part. Japan will host the next event in 2019.