Cousin Rose made her debut in Series 3 following the death of Sybil (Jessica Brown-Findlay) and will become a permanent arrival in the new series, which begins filming soon.

James told Radio Times: “It’s nice to bring the outside world into Downton. The London world is quite exciting – it gives it a social context. Downton’s in a bubble with their morals and the world they uphold, so it’s nice to see the more rebellious London world [as well].”

Discussing her co-stars, Laura Carmichael (Edith) and Michelle Dockery (Mary), she added: “They’re the best! I feel extremely lucky, happy and welcomed. They’ve been doing it for three years, so it’s a big thing to step into the story they’ve created. But I watch it so I know the characters!”

A fourth series and Christmas 2013 special were confirmed by ITV in November.

What are your hopes for Series 4? Let us know below…

> Order Series 4 on DVD on Amazon.

> Buy the complete Series 1-3 boxset on Amazon.

Watch the Series 3 trailer…