grinned as he pulled a pint on a visit to a family-run brewery in Burton Upon Trent in Staffordshire.

The 76-year-old monarch poured a minimal head on the beer as he got behind the bar alongside Tower Brewery owner John Mills. The brewery is an independent, family-run brewery that has been in the local area for 24 years.

It comes after the King walked through an impressive mechanical guard of honour as he arrived at JCB World Headquarters in Rocester, Staffordshire, this morning.

The 76-year-old monarch attended the site to celebrate the 80th anniversary of JCB - the iconic British construction equipment company - and wished the company "many happy returns".

Charles was given a tour of JCB World Headquarters, in Staffordshire by billionaire chairman Lord Bamford.

He walked the backhoe loader assembly line, viewing the wheels of the backhoe digger being fitted and helping fit a wheel with team leader Becky Bayliss, 32, who said his effort was "perfect".

Speaking afterwards Becky said: "He was a little unsure if he managed to get the nut all the way up but the way he handled it was perfect."

Earlier this year JCB celebrated the production of its one millionth backhoe loader, a machine that was invented by JCB's founder, the late Joseph Cyril Bamford CBE. The backhoe is claimed to have changed the world, replacing 'the man with a shovel'.

Charles later helped fill up a new JCB Backhoe Loader with hydrogen and greeted 100-year-old Ken Harrison who worked on the original factory floor when it opened in 1945.

Meeting Ken, who worked for JCB for 36 years, he said: "Are you sure you should be here today? I'm very impressed. It must have done some good, I must say, to get to one hundred."

Charles added: "I hope you got your message on your hundredth birthday? I'm so glad the system works."

Around 3,500 staff, almost the entire workforce, lined up outside waving Union Flags to cheer the King as he departed.

JCB was founded in 1945 and is the world's third largest construction equipment company by volume, with 22 plants on four continents, and employs 7,500 people in the United Kingdom.