WARSAW - Spain will try to become the first team to win three successive major international titles while Germany will hope to lift their first trophy since 1996 when Euro 2012 kicks off on Friday.
The backdrop of the three-week tournament being staged by Poland and Ukraine across a vast stretch of eastern Europe has already been partly defined by off-field events.
It will be the last Euros with 16 countries, often regarded as the "perfect" formula for a knockout event, because UEFA has agreed to expand the finals to 24 teams in France in 2016, an awkward number that blighted World Cups between 1982 and 1994.
Also no other European Championship is likely to face the infrastructure problems that have dogged this tournament since it was awarded to the co-hosts in April 2007.
Ukraine has continually risked losing its right to stage its half of the event and their hoteliers have been described by the UEFA president Michel Platini as "bandits and crooks".
Lastly, the social and political issues surrounding the first major sporting event to be staged in former communist countries since the 1980 Moscow Olympics, could still endanger the tournament's overall success.
There have already been diplomatic ructions between Ukraine and some western European nations threatening to boycott the event at government level over the jailing of former Ukraine Prime Minister Yulia Tymoshenko.
On Tuesday, three days before the tournament starts, a crowd of Ukrainians, angry over a parliamentary vote that would increase the role of the Russian language in the country, clashed with police at a fan zone set up in the capital Kiev.