World leaders have paid tribute to former German chancellor Helmut Kohl – who oversaw German reunification.
Mr Kohl, who died last month, was a major driving force behind closer European integration.
Speaking next to his coffin, which was draped in the EU flag, Chancellor Angela Merkel said it was up to this generation to preserve his legacy.
After the event at the European Parliament, he will be buried in the German town of Speyer later.
It is the first time that the European Parliament in Strasbourg has paid tribute to a leader in such a way.
Mr Kohl worked for German reunification as others hesitated, Mrs Merkel said, adding that his motivation was always that there should be no more war in Europe.
“Now it’s up to us to preserve your legacy. I bow before you and your memory in gratitude and humility,” she said.
She also offered personal thanks for the opportunities that Mr Kohl – her political mentor whom she later denounced over a funding scandal – had given her in her career.
Former US president Bill Clinton also delivered a eulogy.
“All of us who came – why? Because Helmut Kohl gave us the chance to be involved in something bigger than ourselves. Bigger than our terms of office, bigger than our fleeting careers,” he said.
Other speakers included French President Emmanuel Macron, Russian Prime Minister Dmitry Medvedev and former Spanish prime minister Felipe González.
Channelling the Kohl spirit – BBC’s Hugh Schofield in Strasbourg
In effect this has been the EU’s first ever state funeral.
And if it’s been conducted with such a sense of ceremony it’s because the new leaders of Europe – especially Emmanuel Macron and Angela Merkel – want to capture and distil something of Mr Kohl’s spirit, which worked to such effect a quarter of a century ago.
After Europe’s farewell comes Germany’s. Mr Kohl’s body is being transported to his hometown of Ludwigshafen and from there by river boat to the cathedral in the medieval town of Speyer – a 1,000-year-old building that he loved and said symbolised the essence of European union.
The ceremony was proposed by European Commission President Jean-Claude Juncker, who was nicknamed “Junior” by Mr Kohl and who described him as a mentor and friend.
More than 2,000 police have been on duty in Strasbourg.
However Germany will not hold a state funeral for Mr Kohl in Germany at the request of his widow Maike Kohl-Richter, his second wife.
That decision has been criticised by Walter Kohl, Mr Kohl’s son by his first wife, who wanted a farewell ceremony near the Brandenburg Gate in Berlin, near the site of the former Berlin Wall.
Walter Kohl has described the European Parliament commemoration as “unworthy” in an interview with German newspaper Die Zeit.