The groups and fixtures have been announced for the Euro 2016 Championship in France.
Northern Ireland will face world champions Germany, along with Poland and Ukraine in Group C.
But it's group B that lots of people are talking about, because for the first time in a major tournament England will play against Wales.
Here's everything you need to know about the countries involved.
Euro 2016 chances: France were the last host nation to win the title, in 1984, and are among the favourites this time.
Euro wins: Winners in 1984, as hosts, and 2000. This is their seventh successive Euros finals.
Key player: Blaise Matuidi. There are more celebrated French players, but 28-year-old Matuidi is the driving force in midfield, breaking up the opposition's play and springing forward with massive energy.
Who's the boss? Deschamps, 47, led the team to the World Cup quarter-finals in 2014, where they lost 1-0 to Germany. As a player, he captained France to victory at the 1998 World Cup and Euro 2000.
Euro 2016 chances: Romania have the disciplined team attitude and strong defence that was characteristic of Greece's shock Euro 2004 triumph, with a world ranking of 16th.
Euro wins: They reached the quarter-finals in 2000 by beating England with a last-minute penalty. It is their only victory in 13 European Championship matches.
Key player: Vlad Chiriches. The 26-year-old centre back is an important part of Romania's defence.
Who's the boss? Anghel Iordanescu was appointed for the third time in October 2014; he initially turned down the role but was persuaded because of his experience. Iordanescu, 65, guided Romania to three successive major tournaments in the 1990s and was also in charge from 2002-04. He quit football a few years later and served as a senator between 2008 and 2012.
Euro 2016 chances: The influence of their Italian coach is clear - they are organised in defence, sit deep and frustrate the opposition, hoping to snatch a goal from set-pieces or long shots. They did well against Portugal in qualifying, winning 1-0 away.
Euro wins: It's their first time in the competition.
Key player: Basel midfielder Taulant Xhaka, 24, stands out for his technical ability and confidence on the ball. A former Swiss under-21 international, he's the elder brother
Who's the boss? This is not the first time Italian Gianni de Biasi, 59, has found unexpected success - he led Italian club side Modena to Serie A in 2002 after back-to-back promotions. His last club job was with Udinese, who sacked him in 2010.
Euro 2016 chances: There are high hopes for the team despite the fact they have never reached the knockout stage at a European Championship. They progressed to the last 16 at the 2014 World Cup and their regular starting line-up all play for top clubs in Germany, England or Italy.
Euro wins: They've finished bottom of their group in all three previous appearances.
Key player: Stoke's Xherdan Shaqiri, 24, is Switzerland's key creative force and also top scored in qualifying with four goals
Who's the boss? Vladimir Petkovic, 52, took over from Ottmar Hitzfeld after the 2014 World Cup. Multi-lingual Petkovic worked for a homeless charity between 2003 and 2008 while coaching lower league Swiss clubs in the evenings.
Euro 2016 chances: After the 2014 World Cup comes hope that England's squad have learned some valuable tournament lessons. Unlike Euro 2012, when Roy Hodgson took charge a month before the finals, he has had since September to plan ahead, with England having breezed through qualifying.
Euro wins: Third of the four finalists in 1968, England were also semi-finalists as hosts of Euro 96. Euro 2012 was England's best so far. They were unbeaten aside from a quarter-final exit on penalties against Italy.
Key player: Euro 2016 will be the sixth major tournament for England's record goalscorer Wayne Rooney, but the 30-year-old's first as captain
Who's the boss? This will be 68-year-old Roy Hodgson's third major tournament as England boss as he looks to secure an extension to a contract that expires after Euro 2016. Hodgson has managed 14 club sides and four national teams.
Euro 2016 chances: Winless at the 2014 World Cup, Russia have improved since Fabio Capello's sacking in July this year. Replacement Leonid Slutsky made the defence better with players from Champions League regulars CSKA Moscow, who he also manages.
Euro wins: Winners as the Soviet Union in 1960, and finalists in 1964, 1972 and 1988.
Key player: CSKA Moscow defender Sergei Ignashevich. Russia's rock is now 36 but is still really important.
Who's the boss? Leonid Slutsky was rewarded for rescuing Russia's Euro 2016 campaign with a contract until after the finals. He is no stranger to playing the hero - aged 19 he rescued a cat stuck up a tree; unfortunately he fell and got a knee injury, which ended his footie career.
Euro 2016 chances: Wales have had a 58-year wait to play in a major tournament. Gareth Bale's goals propelled them to France, but captain and defensive rock Ashley Williams is equally as important.
Euro wins: Newbies at a 'finals'. Reached the quarter-finals in 1976.
Key player: Real Madrid forward Gareth Bale scored seven of Wales' 11 qualification goals. Things aren't going quite so well at club level, but the world's most expensive player can do no wrong for Wales.
Who's the boss? Chris Coleman took over in 2011. Booed regularly at the start, with a 6-1 World Cup qualifying defeat in Serbia, Coleman has now extended his contract beyond 2016.
Euro 2016 chances: Slovakia will be appearing at just their second major tournament in 11 attempts since 1993. They reached the last 16 at the 2010 World Cup, helping to knock out Italy in the group stages. They also beat Spain in qualifying for Euro 2016.
Euro wins: This is their first appearance.
Key player: Napoli and Slovakia captain Marek Hamsik. The attacking midfielder top scored in qualifying with five goals.
Who's the boss? Former Czechoslovakia international Jan Kozak was appointed in July 2013. The 61-year-old had previously managed several Slovakian league clubs.
Euro 2016 chances: They may be joint favourites with hosts France, but the world champions scored 36 goals in qualifying for the World Cup in Brazil, but just 24 to reach Euro 2016.
Euro wins: Winners in 1972, 1980 (both as West Germany) and 1996. They reached the semi-finals in 2012, when they lost 2-1 to Italy.
Key player: Bayern Munich's brilliant forward Thomas Muller. Known as the Raumdeuter, or 'space investigator', he top scored for Germany with nine goals in nine qualifiers.
Who's the boss? Joachim Low masterminded Germany's first trophy since Euro 96 by winning the 2014 World Cup after years of careful planning. Euro 2016 marks ten years in charge and he has a new contract to 2018.
Euro 2016 chances: They had a good defensive record in qualifying, conceding five times in 12 games.
Euro wins: This is the first time Ukraine have qualified.
Key player: Andriy Yarmolenko got 22 goals from 55 appearances.
Who's the boss? Mykhaylo Fomenko took over in 2012 and saw Ukraine narrowly miss out on qualification for the World Cup, losing a play-off 3-2 on aggregate to France.
Euro 2016 chances: Robert Lewandowski makes them a strong side, along with Sevilla's defensive midfielder Grzegorz Krychowiak, who was named in La Liga's team of the year last season.
Euro wins: This is only the second time they have qualified. They failed to win a game in 2008 or as co-hosts in 2012.
Key player: Bayern Munich's Lewandowski, 27, is arguably the world's best number nine right now - scoring 30 goals in his first 28 games this season for club and country.
Who's the boss? Appointed in October 2013, Adam Nawałka, 58, played for Poland at the 1978 World Cup.
Euro 2016 chances: Team spirit and dead-ball deliveries will be important. They scored nine goals from set-pieces in qualifying, more than any other nation.
Euro wins: This is the first time they've qualified.
Key player: Kyle Lafferty, 28, scored seven times in nine qualifying games.
Who's the boss? Michael O'Neill's success has not come overnight - the former Shamrock Rovers boss was appointed in 2011, and won just one of his first 18 games in charge.
Euro 2016 chances: Most of the current side were part of Spain's Euro 2012 triumph.
Euro wins: Spain became the first side to retain the trophy when they beat Italy 4-0 in the 2012 final. They also won in 1964.
Key player: Manchester City's David Silva. He usually starts on the right of a three-man attack but roams around the pitch to operate in pockets of space and creates openings.
Who's the boss? Vicente del Bosque, 64, marked a national record 100th match in charge of Spain in June 2015 and he has hinted at staying on beyond Euro 2016.
Euro 2016 chances: No standout stars, but the Czechs performed better than expected in qualifying.
Euro wins: They have now qualified for the finals six times in a row 1993. The Czechs were runners-up in 1996, semi-finalists in 2004 and quarter-finalists in 2012.
Key player: Petr Cech. The team's captain is set to play at his fourth European Championship, when he will be 34.
Who's the boss? Pavel Vrba, 52, has been named Czech Coach of the Year for five seasons running.
Euro 2016 chances: They conceded just three times in their last seven matches and beat the Dutch 3-0 and Czechs 2-0. Their Fifa world ranking of 21 is their highest since 2009.
Euro wins: This is their fourth appearance. They reached the semi-finals in 2008.
Key player: Midfielder Arda Turan, 28, now at Barcelona, was important in Atletico Madrid's La Liga triumph in 2014.
Who's the boss? Fatih Terim - 'The Emperor' - started his third spell in charge in 2013. In his first (1993-96) they qualified for their first European Championship. In his second (2005-2009) they reached the semi-finals of Euro 2008.
Euro 2016 chances: With a midfield including Ivan Rakitic and Luka Modric they're the envy of coaches the world over. Mario Mandzukic has been one of Europe's best strikers over the last few years.
Euro wins: This is their fourth appearance in the finals, and their fifth in total. They reached the quarter-finals on debut in 1996 and again in 2008.
Key player: Midfielder Rakitic. He won the treble in his first season and scored the opener in the 2015 Champions League final.
Who's the boss? Ante Cacic took over for the final two qualifiers. He had previously managed Dinamo Zagreb, Lokomotiva Zagreb and Slovenian side Maribor.
Euro 2016 chances: Ranked by Fifa as the best country in the world, Belgium will arrive in neighbouring France with pressure to justify that tag.
Euro wins: Belgium are in the finals for the first time since 2002 when, as co-hosts, they left at the group stage. They were runners-up in 1980 and third in 1972.
Key player: De Bruyne, 24, was important in the qualifying campaign.
Who's the boss? Marc Wilmots, 46, will celebrate four years in charge next June. He went to four World Cups as a player with Belgium and, as coach, took them to the quarter-finals of the 2014 World Cup.
Euro 2016 chances: They are a working hard under boss Antonio Conte, who has tried both 3-5-2 and 4-4-2 formations.
Euro wins: Winners at home in 1968 and finalists in 2000 and 2012.
Key player: Graziano Pelle, who plays for Southampton, is praised for his fast footie skills.
Who's the boss? Antonio Conte, 46, won three consecutive league titles with Juventus.
Euro 2016 chances: Impressive matches against Germany and Bosnia-Herzegovina show they have a strong game-plan, meaning they will have realistic hopes of reaching the knockout stage of the European Championship for the first time.
Euro history: They failed to advance from their group in the last two competitions (1988 and 2012), losing all three Euro 2012 games.
Key player: Stoke City striker Jon Walters, 32, was his country's outstanding performer in qualifying.
Who's the boss? Martin O'Neill is recognised for turning Irish fortunes around.
Euro 2016 chances: A lot rests on Zlatan Ibrahimovic, who is captain, and national icon.
Euro wins: This is their fifth Euros in a row, and their sixth in total. Their best performance was in 1992, when they made the semi-finals.
Key player: Ibrahimovic, after eleven goals in qualifying, including three in the play-offs.
Who's the boss? Erik Hamren has been Sweden boss full-time since 2010.
Euro 2016 chances: After a poor 2014 World Cup, results have improved under their new manager.
Euro pedigree: They have reached at least the quarter-finals in the last five tournaments. Beaten finalists on home soil in 2004, they were semi-finalists in 2000 and 2012.
Key player: Cristiano Ronaldo, who else? The three-time world player of the year scored five goals in six qualifying appearances, but he has not been at his brilliant best for Real Madrid this season.
Who's the boss? After ending his playing career at the age of 21, Fernando Santos worked as an electrician before taking up coaching.
Euro 2016 chances: In 2011 they qualified for the European Under-21 Championship for the first time, and several of those players have stepped up to senior level.
Euro wins: This is their first time at the Euros.
Key player: Swansea's Gylfi Sigurdsson top scored with six goals in qualifying, including all three of the goals they scored in the two wins over the Netherlands.
Who's the boss? Swede Lars Lagerback, 67, is joint coach with Heimir Hallgrimsson.
Euro 2016 chances: Hopes are high after a strong qualification campaign which helped Austria climb into the top 10 of the Fifa rankings for the first time.
How they qualified: Austria were unbeaten in Group G, winning nine of their 10 matches to finish eight points clear of Russia.
Euro wins: This is only their second appearance and the first time they have qualified for the finals. They failed to win a game as co-hosts at Euro 2008.
Key player: Central midfielder for his country, David Alaba is a favourite.
Who's the boss? Former Switzerland international Marcel Koller.
Euro 2016 chances: It's been 30 years since they've qualified. Not a single member of their squad plays regularly in any of Europe's top five leagues and they would appear to be among the weakest sides heading to France.
Euro wins: They did well in the competition's early tournaments, finishing third in 1964 and fourth in 1972. They then failed to qualify for 10 finals in a row, until now.
Key player: Balazs Dzsudzsak. The 28-year-old left winger and captain helped them qualify. He has played regularly in Hungary, the Netherlands and Russia and is currently with Turkish side Bursaspor.
Who's the boss? German Bernd Storck, 52, took over in July. Most of his coaching career has been in Kazakhstan. He played for Borussia Dortmund in the 1980s.