Downton veteran Dame Maggie Smith was in fits of laughter on the ITV set - after her onscreen granddaughters showed her a series of rude clips on YouTube.

Jim Carter, who plays butler Carson in the hit drama, told how Michelle Dockery, Laura Carmichael and Lily James would surprise the star with the videos to prompt a reaction. And he told how Dame Maggie never failed to disappoint, frequently dissolving into giggles with the girls in between takes for the latest series.

Jim said: “Michelle, Laura and Lily treat Maggie like their real grandmother - they show her rude things from YouTube. In between takes they all play games, they gossip and have fun.”

He went on: “Maggie is as witty as the Dowager Countess. It’s the fourth or fifth time I’ve worked with her and she loves it, she is on great form. Julian Fellowes writes really well for her. And what is lovely is that I get to see her more than Phyllis Logan, who plays Mrs Hughes.”

Despite enjoying his role in the ITV series, which returns on September 21, Jim admitted filming dinner party scenes as a butler can be tedious and tiring. And he joked he has won medals for his patience.He said: “Stand in that corner for the rest of the afternoon while everyone is talking about something else and see how you like it. Every time there is a dinner party scene, think of that waistcoat in the background that occasionally comes in with a carafe of wine. And think that that was ten hours of my life - I get medals for patience.” (x)