The pool draw for the 2019 Rugby World Cup in Japan took place on Wednesday.
Here, we look at how the pools shape up for Ireland, Scotland, England and Wales.
Ireland: Will start the group as favourites, but their World Cup record is not great, having never progressed beyond the quarter-finals, while clashes against Scotland and host nation Japan could be testing.
Scotland: New head coach Gregor Townsend will undoubtedly have made a mark by the time 2019 comes around, and the Scots will hold strong quarter-final ambitions. Topping the group is not beyond them.
Japan: How Japan cope with host nation pressures will be fascinating, but they proved their capability by stunning South Africa in World Cup rugby's biggest upset in 2015. Ireland and Scotland cannot take them lightly.
Europe 1: This qualifier will be the 2017-18 Rugby Europe Championship winners. Romania are current favourites, but they are unlikely to feature at the World Cup group's business end.
Play-off winner. The third team in the 2016-17 Pacific Nations Cup - probably Tonga - will face the Rugby Europe Championship runners-up, possibly Spain. Tonga would not be pushovers.
England: Have been in prolonged impressive form under head coach Eddie Jones, but a similarly tough group at the 2015 World Cup - England were drawn with Australia and Wales - saw them fail to reach the knockout phase under Jones' predecessor Stuart Lancaster. England should win the group, but it might not be straightforward.
France: Showing signs of a revival under Guy Noves' coaching guidance, and they beat England in the countries' last World Cup meeting six years ago. If Noves can develop a successful and consistent style of play, then Les Bleus could trouble any one.
Argentina: Semi-finalists in two of the last three World Cup tournaments, the Pumas are a powerful force and potentially England's toughest pool opponents. Argentina are capable of rocking any team on their day, and England are no exception.
Americas 1: The United States are favourites to fill this berth, and while England should encounter few problems against them, they should not forget a 2007 pool game in Lens, when they were pushed all the way before claiming a 28-10 win.
Oceania 2 - Fiji or Samoa are set to be the second Oceania qualifier. Again, England should be too strong, but it could prove hard work.
Australia: World Cup winners in 1991 and 1999, the Wallabies will be favourites to win the group, but they can expect some testing moments along the way.
Wales: Warren Gatland's men lost to Australia in the last World Cup, while they have suffered 12 successive defeats against them. Georgia's visit to Cardiff for an autumn Test in November now takes on greater significance, and Wales must also brace themselves for a likely collision with Fiji or Samoa.
Georgia: Qualified by right for the first time in World Cup history, and they are an emerging force. Powerful up front, Georgia will not roll over for anyone, and Australia and Wales must be on full alert.
Oceania 1: Fiji or Samoa are likely to fill this berth. Wales beat Samoa at the 2011 World Cup, and then Fiji in 2015, but both games were fearsome physical encounters when Wales were tested all the way.
Americas 2: This spot will be filled by the United States, Canada or a South American qualifier, and while they should not trouble Wales unduly, they are not opponents to be treated lightly.