On Monday, Kylian Mbappé and his France enter the tournament. But also Ukraine, who are playing for a greater purpose.
Here are all the prerequisites for today's matches.
On the fourth day of the championship, one of the heaviest favourites for the gold medal enters the tournament. France begins the group stage against Austria in the evening match in Düsseldorf.
Belgium is also tipped - as usual - by many experts as a possible final winner in Berlin in a month's time.
Here are the prerequisites for Monday's three matches:
What: Romania-Ukraine, Group E.
When: Monday, 17 June, 15.00.
Where: München Fußball Arena (Allianz Arena).
TV/Radio: SVT/SVT Play/P4 Radiosporten.
+ A reminder of the war
Ukraine is in the European Championship to win football matches. But also to remind the world about the war that is plaguing the country. Coach Sergej Rebrov mentioned it earlier during the championship.
It's a war we're fighting for the whole of Europe, he says.
+ Thinking of the soldiers
Before the European Championship premiere, Arsenal player Oleksandr Zintjenko - who was in the European Championship 2021 when the team reached the quarter-finals after beating Sweden - sends an extra thought to the soldiers in combat and their families.
For them, it's extremely difficult, for us, it's clearly an extra motivation. We all know who's behind us. We must show our best, he says.
What: Belgium-Slovakia, Group E.
When: Monday, 17 June, 18.00.
Where: Frankfurt Arena
TV/Radio: TV4/TV4 Play/P4 Radiosporten.
+ Playing to unite the country
The attempted murder of the country's Prime Minister Robert Fico has shaken Slovak society. Marek Hamsik, you remember him from a shorter stint at IFK Göteborg, is now the assistant coach and hopes that the European Championship can bring the Slovaks together.
It's terrible times for Slovakia. I couldn't imagine in my wildest fantasy that it would happen, says Hamsik.
As a player, he scored 26 national team goals in 138 national team matches, and he sees the national team as a unifying factor.
Sport has always brought people together and lifted the mood in the country. I hope the people support us and that it makes people put aside their differences, says Hamsik.
What: Austria-France, Group D.
When: Sunday, 16 June, 21.00.
Where: Düsseldorf Arena.
TV/Radio: TV4/TV4 Play/P4 Radiosporten.
+ Back to Berlin?
It's been 18 years since France lost the World Championship final against Italy after a penalty shootout. The venue? Olympiastadion in Berlin. And where is this year's European Championship final being held? Exactly, at the same arena.
+ He has won everything
Didier Deschamps, France's long-standing coach, lifted the European Championship trophy as a player in 2000. Two years earlier, he won the World Championship at home in Paris, a title Deschamps also won as coach in Moscow in 2018. Now he has the chance to make history and also win the European Championship as coach.
Whatever happens, he has made an indelible mark on French national team football. The European Championship is the only thing he's missing as a coach, and we need to do something extra for him to fill in all the boxes, says star striker Kylian Mbappé in an interview with Ouest-France.
If they play, Mbappé will make his 80th national team appearance, and Antoine Griezmann will become only the fourth French player to reach 130 national team appearances.
+ Political unrest
Emmanuel Macron, France's President, has announced elections to the National Assembly in less than two weeks. Several players, including Marcus Thuram and Ousmane Dembélé, have expressed strong opinions about the situation in the country after the European election successes for the National Rally.
+ In top form
Austria eliminated Sweden from the European Championship playoffs and enters the tournament with a seven-match unbeaten streak - and with only three conceded goals during the period. Coach Ralf Rangnick has a fully fit squad ahead of the match against France.