In the first series the interior of Thames house was filmed in a college in Kensington, the night shots of the beach shown in Episode 2 ("Looking After Our Own") were actually filmed on the cobbled courtyard outside the university.
Kevin McNally's character asserts (at about 7:10) that England's never had a revolution because of John Wesley's Methodist preaching. In [title=tt0075560], Kevin McNally played a Methodist character named Drake Carne who lived at a time when Methodists were treated repressively in England.