Afterward Mr Reardon, who is from Merthyr Tydfil, said: “He mentioned going to the gym… He said, ‘You’re opening a gym are you?’ I said, ‘Yeah’.

“I said, ‘Look, if you’re ever in the area again and you fancy a session, I’ll put you through your paces’. He said, ‘Oh, yeah, I’d love to’.

“I said, ‘You look fit anyway’, he said ‘I train twice a day’, I said, ‘I can tell’.”

The guests, who included Gavin and Stacey star Ruth Jones, sang Happy Birthday to the King before he cut his cake – a vanilla sponge, with jam and buttercream made to look like Cyfarthfa Castle.