Lord Sinderby's ancestors came from Russia. In England they made a fortune and acquired the title of Baron Sinderby. Lord Sinderby himself is a prominent figure in England's Jewish community, proud of his faith and his family's achievements.
His grandfather changed the family's name to Aldridge. He himself considered changing it back, but his family felt they were English now and wanted to remain English, so he did not.
Lord Sinderby and his wife make the acquaintance of the Crawley family through their cousin Lady Rose MacClare, who has formed a relationship with Lord Sinderby's son, Atticus. Later invited to Downton with his wife and son, Lord Sinderby speaks with Lady Grantham about her Jewish father, Isidore Levinson.
Lord Sinderby, unlike his wife, does not approve of his son's growing attachment to Rose and their eventual engagement, because he does not wish for Atticus to marry out of the faith. As he explains on the day of the wedding, any children Atticus has with Rose will grow up Anglican, not Jewish (although Atticus insists their children will grow up knowing both religions, and that they might convert to Judaism).
When Atticus is set up at his bachelor's party, he and others in both families suspect Lord Sinderby might be responsible. Lord Sinderby denies this (as it was actually Rose's mother, who did not approve of her daughter's bridegroom being Jewish). Later Rose admitted such an act was not Lord Sinderby's style. He himself did nothing further after his wife threatened to leave him if he did anything to stop the wedding.
Later that year, he rents Brancaster Castle in Northumberland and invites the Crawley family there for the grousing season. While renting the castle, he brings along with his family his butler, Stowell. He is fond of Stowell, but the latter is revealed to think badly of the Aldridge family behind their backs. Mary Crawley asks Barrow to try and humiliate Stowell after Stowell repeatedly treats her brother-in-law rudely because of his background. Later, after being given a bland dinner due to a fake letter given to the cook, Lord Sinderby is displeased and upset when Stowell talks to him in a disrespectful manner.
Later, a young woman named Diana Clark shows up at an afternoon tea after out grousing unannounced with her son. The Lady Rose intervenes on his behalf and saves him from ridicule and embarrasment and takes Diana as her immediate friend that she had invited to the party. It is revealed Diana is his lover and her son is his illegitimate child. Lord Sinderby then pulls Robert, Lady Rose, and Lady Mary and apologizes to them and thanks them for interceding on his behalf and asks them to keep the secret which Robert, and Lady Mary agree to. Lady Rose endears herself to Lord Sinderby by keeping his confidence and he is thankful to have her in the family.
- In Episode 3 of Series 6, Lord Sinderby is only mentioned in passing by Bertie Pelham in response to Edith's mention of Rose.
|Appearances and Mentions|
|Series 5||Episode 1||Episode 2||Episode 3||Episode 4||Episode 5||Episode 6|
|Series 6||Episode 1||Episode 2||Episode 3|
|Episode 4||Episode 5||Episode 6||Episode 7||Episode 8|
- ↑ Baron is the only rank of the Aristocracy that is addressed, both in correspondence and verbally, as "Lord [title]", which is how Lord Sinderby is addressed, meaning he has to be a Baron.