After the entertainment world paid a musical tribute to the monarch in the shadow of Buckingham Palace, the Queen walked out in front of the crowds and set the national beacon ablaze.
She carefully placed a crystal glass diamond into a special pod, triggering the lighting of the last beacon, in The Mall.
A network of beacons, placed on historic landmarks, hill-top vantage points and famous mountains, criss-crossed the UK.
On Hadrian's Wall, 60 beacons were lit in sequence – one for each year of the Queen's reign.
Closer to home a giant beacon was set alight on a landmark hill near Glasgow to mark the Diamond Jubilee.
The beacon was lit on the summit of Dumgoyne in the Campsie Fells, by Strathblane.
It was among 200 beacons lit across Scotland.
Volunteers from Strathblane, in Stirlingshire, spent Friday assembling the massive bonfire atop the 1050ft hill.
The beacon was the brainchild of Reverend Richard Begg, minister at Strathblane Parish Church.
It was visible from Glasgow, 10 miles away, and at Loch Lomond.
In Edinburgh, a beacon was lit on the battlements of the castle, raising a cheer from crowds gathered on Princes Street.
Fires were lit from Land's End to John O'Groats, with special ceremonies held on the nation's four highest peaks. On Ben Nevis, soldiers from Help for Heroes lit the beacon.
Earlier yesterday a crowd sang God Save The Queen as a beacon was lit in the town of Blenheim, in Marlborough, New Zealand.
Meanwhile, in Australia, prime minister Julia Gillard lit a beacon at Parliament House in Canberra.