By Channel 4 News, More4 News
Communism fell in eastern Europe 20 years ago. But did unification and European expansion come too fast? And has Europe lived up to the promise offered by the Berlin wall's toppling on 9 November 1989?
It was sudden, and with hindsight perhaps inevitable. Communism fell in eastern Europe just twenty years ago - terminating a European division that many feared would stand for all time.
Twenty years since the world changed for ever: 20 years since millions got their first taste of freedom: twenty years since the Berlin wall came tumbling down.
World leaders joined thousands of people at the city's Brandenburg gate to remember the events that finally brought an end to the cold war. Germany's Chancellor Angela Merkel described it as "the fulfilment of a dream".
The celebrations culminated in a massive concert and fireworks display, with 1,000 dominoes toppling along the site where the wall once stood.
Jens Reich, one of East Germany's main opposition leaders in 1989, told Channel 4 News it was a "happy day".