Jude Law has hosted a concert marking the opening of the London 2012 festival in Londonderry.
Pixie Lott, Newton Faulkner and Imelda May headlined the Peace One Day bill at a former military barracks which has been transformed into a shared arts space linked to the heart of the city.
Northern Ireland's second largest city was once the cockpit of the conflict, world famous for the Bloody Sunday shooting of civil rights demonstrators by British soldiers and years of pitched battles between republicans and the security forces.
Now it is relatively settled and much of it has prospered from a peace process started two decades ago. The musicians joined Peace One Day founder Jeremy Gilley for the show ahead of Derry's year as UK city of culture in 2013. He said the event celebrated world peace and global truce.
"It is inspiring talking about a truce or peace. You could not be in a better location. This is why we can have this concert here," he said. "The square, which was Ebrington Barracks which housed soldiers, is now housing beautiful music."
The London 2012 festival is the finale of the Cultural Olympiad. Since the Cultural Olympiad started in 2008, more than 18 million people all over the UK have participated in or attended more than 9,000 performances and 8,000 workshops.
The concert is part of a wider series of events promoting the Global Truce campaign backed by London 2012 chairman Lord Coe and secretary general of the UN Ban Ki Moon. Its culmination will be a Peace One Day concert in London at which Elton John will perform on September 21.
Tickets for the event, which kicks off a summer of Olympic Games celebrations, were offered free after film producer Michael Hamyln offered to pay for them. He said it would put Derry on the map for the right reasons.
Ebrington is expected to host more than 40 major events throughout the city's year as UK city of culture. It is in the mainly unionist Waterside, linked to the mainly nationalist Cityside of Londonderry by a new pedestrian Peace Bridge over the River Foyle.
Stormont Culture Minister Caral Ni Chuilin said the festival offered people the opportunity to get involved in the London 2012 Games. "This is an exciting day. The Ebrington site with the stunning backdrop of Derry city certainly showcases the future city of culture 2013 at its best," she said.