Anyone passing Home Park in Windsor this weekend may have been surprised to see King Charles and Queen Camilla skipping across a field next to the town's iconic castle. 

But closer inspection would have revealed that the pair were not the nation's real monarchs but activists taking part in a three-day protest camp set up by Extinction Rebellion. 

More than 50 tents and 100 activists made up the camp, with scientists, former airline pilots, and even a gold-medal winning Olympic canoeist all attending. 

Plans for the camp had caused concern that the passionate environmentalists intended to storm Windsor Castle or other local attractions and business as a form of direct action protest. 

Additional metal fencing had been placed around the castle, while Thames Valley Police had issued a statement saying any law-breakers would be dealt with "robustly."

Meanwhile, the Royal Borough of Windsor and Maidenhead had said they did not support the "festival" - nor had they given permission for it to take place in the council-managed park. 

But the three-days of  camping, activism workshops, and theatrical stunts appeared to go ahead without causing major disruption in the area. 

Stunts included delivering a letter for King Charles at Windsor Castle, urging the king to be more active on environmental issues. 

Etienne Stott, who won gold in the two-man canoe slalom in the London 2012 Olympics, said he had attended to help highlight the damage being done to environments and communities across the UK and abroad. 

He reiterated calls from Extinction Rebellion spokespeople who had denied there had been any plans for storming the town's castle. 

Mr Stott said: "All different groups have their different tactics and way of doing things - we see ourselves as part of an ecosystem of change.

"What we all need to do is communicate the severity of this issue."

Conservationist Dr Charlie Gardner said there was a "wonderful spirit" among the camp attendees despite the severity of the issue being highlighted. 

Dr Gardner said: "The global scientific community has addressed all this data that shows we need to protect nature - and our governments are essentially ignoring it. That's why I'm here, calling on our government to upgrade democracy to deal with this issue."

Former airline pilot Todd Smith agreed: "It's great to be around people who understand the scale of the problem we are facing as humanity. I'm just grateful to be here with the community."

And the group's litter-picking efforts after the event won praise from Windsor councillors. 

Helen Price, the councillor for the Clewer and Dedworth East ward, said the area had been left "clean and tidy."

She said: "I popped down there this...I thanked volunteers there for ensuring it was a peaceful protest and leaving everything so clean, and also the PCs who told me it all went well."