In the past on several occasions I have noted here how much of a small, small world it is when it comes to the general size of the acting pool in Great Britain. There's crossovers all the time, and it always makes me cackle when I recognize an actor making the jump from one BBC program to another or over the pond to America.
Take Downton Abbey, for instance. I've spotted three so far just in the first two seasons: First, there was the ginger-haired housemaid, Gwen, in Season 1 - the gal that wanted to be a secretary. She's also Ygritte the Wildling in Game of Thrones. (Actress Rose Leslie)
And speaking of GoT, how's about Iain Glen who plays Ser Jorah Mormont? Aka Sir Richard Carlisle on Downton who also starred in a couple of episodes of Doctor Who.
Now here's the ultimate Six Degrees of Downton for the UK: Penelope Wilton who plays Matthew Crawley's mother, Isobel? She too starred in a couple of Who episodes as "Harriet Jones, Prime Minister."