Nevermind the Teletubbies and Bob the Builder - for nearly 25 years Play School was the programme that defined children's TV.
And a host of its former presenters including Johnny Ball and Carol Chell have marked the much-loved show's 50th anniversary with a special reunion.
They were joined by presenter Julie Stevens, now 77, who revealed that there were some blue-blooded fans among its legions of devoted viewers.
She explained how, on a set visit with Prince Andrew, she asked the royal youngster how old he was and he said he was six.
She said: "That's a bit old for Play School. It goes up to five - you'll be watching other programmes soon."
But the Prince replied: "I am going to watch it for ever and ever and ever."
Speaking at the anniversary reunion, held at the Riverside Studios in Hammersmith, west London, Mrs Stevens said it had been an emotional get-together.
She said: "It is unbelievable to see everyone, I had a lump in my throat. Play School was such a family - I don't know why they stopped doing it.
"It was a fabulous programme to do. It had a special place in children's hearts - when their mother came in during the show they would say 'Sshhh'. It was for them and only for them."
The show made its debut on BBC Two's launch on April 21 1964, and ran for 24 years, until March 1988.
It shaped the childhood of millions and catapulted many of its presenters to fame.
Among them was Floella Benjamin - a presenter, actress and writer and now a Liberal Democrat peer.
Modern-day CBeebies star Justin Fletcher, who was at the reunion, said: "Play School always paid such attention to its audience. I try to put a bit of Play School in all my shows."