1970 – The muddy beginnings
Farmer Michael Eavis decides to hold a festival to pay off his overdraft. With tickets costing £1 and free milk provided, 1,500 people descend on Worthy Farm near Pilton in Somerset to watch sets from the likes of T Rex (standing in for The Kinks). Eavis is so enamoured with it he decides to continue.
1981 – Things gets political
The festival takes on a new political direction. Eavis's affiliation with CND attracts politically minded performers including New Order, Taj Mahal and Aswad. It is also the first Glastonbury to turn a profit.
1990 – Pilton is burning
In the 1970s and 1980s, the festival had become part of the alternative summer calendar, which included celebrating the Solstice at Stonehenge and then Glastonbury. Trouble erupts between security guards and travellers and police show up in full riot gear and 235 people are arrested.
1995 – The birth of Britpop
Pulp step in to headline after a last minute cancellation by the Stone Roses. The performance has goes down in festival history as one of the best ever and some say, marked the birth of Britpop. This year The Prodigy also put in a career-changing show.
2002 – The fence goes up
After the fence collapsed the previous year, 2002 sees the unveiling of a new £1m, five-mile perimeter fence with a second barrier that puts an end to people jumping the fence as a way of gaining entry.
2007 – Further controls
The previous year, the £125 tickets had been selling on eBay for more than £750 so a new system is introduced. Punters have to register to buy tickets, then, if successful, are issued passes bearing their name and photo.
2008 – A headline hoo-ha
After a big build up in which Noel Gallagher claimed having a rapper headline Glastonbur was "wrong", Jay-Z takes to the stage and does a storming set.
2011 – Swift sell-out
This weekend Coldplay and Beyoncé will headline alongside U2, who were forced to cancel their 2010 headline slot after Bono had to have surgery on his back. All 137,500 tickets sold out in less than four hours.