Episode #1.2 - S1-E2
Continuity mistake: When Cora (Lady Grantham) goes to Violet (the Dowager Countess)'s house to discuss Matthew and Isobel Crawley, she sits at the table and takes off her gloves shown in a shot from the front, and then the shot changes to over her shoulder and she is seen taking the same glove off again. (00:37:25)
Answer: Lord Sinderby purchased the house, furnished and appointed, from someone else, complete with staff that come with the home (some of whom aren't happy to be working for a Jewish family). He bought the title, as well. If the artwork featuring Jesus is valuable, he might keep it. Also interesting, his ancestors Anglicized their name, though he is proudly Jewish.
Michael Albert