Germany has celebrated 20 years since reunification, with tens of thousands of people turning out to celebrations in the northern city of Bremen.
West and East Germany merged on 3 October 1990, following the fall of the Berlin Wall.
Chancellor Angela Merkel, herself brought up in East Germany, paid tribute to both East Germans for having "the courage to fight for freedom" and to the solidarity of the people of West Germany.
On the eve of the celebrations, US President Barack Obama congratulated Germany, praising "the courage and conviction of the German people that brought down the Berlin Wall, ending decades of painful and artificial separation."
The president said the peaceful reunification of East and West Germany was a "historic achievement.,"
After World War II, the victorious powers, the United States, Britain, France and the Soviet Union carved defeated Germany into four sections.
With the advent of the Cold War, Moscow erected a border between its eastern section and the three western Allied sections, including the Berlin Wall that split Berlin in two.
On 3 October 1990, just under a year after the wall was pulled down in a bloodless revolution, the reunification treaty bringing the two halves of the country together came into effect amid joyful scenes.
There were some protests against the reunification festivities, with around 1,800 mainly left-wing activists conducting a march in Bremen on Saturday evening that passed off peacefully.