The show was presented live from BBC Television Centre in London
The golden anniversary of children's programme Blue Peter has been marked with a specially extended edition of the show on BBC One.
The live show featured a fireworks display at BBC Television Centre in London, and a performance from McFly.
Past and present hosts were shown meeting the Queen at Tuesday's party at Buckingham Palace, and four viewers were presented with gold badges.
Blue Peter is the longest-running children's magazine show in the world.
The current presenters showed off an official certificate from the Guinness World of Records in Thursday's special edition.
Watch some of the best Blue Peter memories from the last fifty years
Newest host Joel Defries became an additional drummer for pop band McFly's performance, which was seen by dozens of Blue Peter viewers.
The programme also looked back at its 50-year history, showing the presenters, pets and "makes" that have made the show famous over the years.
John Noakes, Valerie Singleton, Simon Groom and Konnie Huq were among the ex-presenters in attendance at Buckingham Palace, when the show received its Royal seal of approval earlier in the week.
"Blue Peter has been at the heart of children's lives for 50 years, and we are absolutely delighted that the Queen is recognising this," said editor Tim Levell.
Speaking at Buckingham Palace before the tea party, Peter Purves said he was "seriously thrilled" and "absolutely delighted" to be invited.
"I've always wanted to look inside Buckingham Palace, so now I'll get the chance," joked John Noakes.
Asked to explain Blue Peter's longevity, Singleton said it was down to the show being "a fantastic programme that does so many different things".
"There will always be room for this kind of programme," Purves told the BBC News channel.