Tom Cullen is among the actors stepping into the Downton Abbey world, with the producers of the UK period drama announcing that it’s all change, ahead of its fourth series – with more a handful of new faces mixing with the regulars on the award-winning show.

Those who’ve been watching Charlie Brooker’s warped modern-day drama trilogy Black Mirror on Channel 4 recently will recognize Cullen, who starred in the third and final episode of the first season, and he’ll be joined on Downton by former Eastenders actor Nigel Harman. Harman played Denis Rickman in the BBC One soap and, according to The Huffington Post, he’ll be transferring to the ITV drama as a visiting valet called Green. Cullen, meanwhile, has been cast as Lord Gillingham, an old family friend who, it’s being rumoured, could become a potential new love interest for Lady Mary (played, of course, by Michelle Dockery.)

Tom Cullen

Tom Cullen is among a host of new actors appearing in Downton Abbey

In more appearance news, Dame Harriet Walters is set to join the cast as Lady Shackelton, who is a friend of Maggie Smith’s Dowager, while several guest appearances have been confirmed. The opera star Dame Kiri Te Kanawa will play a singing house guest, with other appearances coming from Joanna David and Julian Ovenden – the pair will play the Duchess Of Yeovil and a visiting aristocrat respectively.