U2 frontman Bono has taken to the stage for the first time since sustaining a spinal injury in May.
The band resumed their world tour in Turin, Italy, where the singer thanked fans for "all the love and letters you've sent me in recent months".
He added: "That's in the past now and I'm very much fit for the future."
Bono had emergency surgery to save him from possible paralysis, forcing them to postpone the US leg of the tour and a Glastonbury Festival headline slot.
In Turin, the band unveiled a new song called Glastonbury - which they had intended to perform at the legendary event.
Festival organiser Michael Eavis has invited them to play next year, and is waiting to find out whether they are available.
They will be in the middle of their rescheduled US tour when the festival takes place next June, but do not have any gigs scheduled for the Friday and Saturday of the event.
U2's manager Paul McGuinness said Bono had trained hard to get back on stage.
"The doctors are very confident," he told the Reuters news agency. "They certified him fit to perform. It's really a very short time for a spinal injury."
Mr McGuinness predicted that it would be the "biggest grossing music tour by anyone of all time" by the end of the year, but added that the band lost around $15m (£9.4m) as a result of the setback, half of which was covered by insurance.