|Duke of Balmoral|
|Spouse||Duchess of Balmoral|
|Children|| Eldest son|
Robert St Simon
Eustace St Simon
Clara St Simon
|Occupation||Former Foreign Secretary|
|Position||Peer of the Realm|
|Behind the scenes|
|Appearances|| "The Noble Bachelor"|
"The Empty House"
The Duke of Balmoral was a British peer and onetime Foreign Secretary for the United Kingdom. He hailed from a very old and noble family, directly descended from both the houses of Plantagent and Tudor. However, in spite of his illustrious lineage and connections he was apparently rather financially strapped, possibly because of a penchant for gambling at horses and cards.
Lord Balmoral was the father of Lord Robert St Simon, who in 1887 became engaged to marry the American heiress Miss Hatty Doran. At the time, the Duke was in a poor financial situation and had recently been forced to sell his picture collection, so many suspected that Miss Doran's hefty dowry was a driving force behind the marriage. However, Lord Balmoral and his eldest son were notably absent from Lord Robert's wedding and the subsequent breakfast, though his wife and younger children did attend.
Lord Balmoral's horse Iris ran in the Wessex Cup the year Silver Blaze went missing. After Sherlock Holmes successfully recovered Silver Blaze, Balmoral lost the race, and Iris came in a bad third behind Silver Blaze and Lord Backwater's horse, Desborough.
Lord Balmoral lost £420 pounds gambling at cards with Ronald Adair and Sebastian Moran at a London club. Sherlock Holmes later realizes that when Adair realized Moran won them this sum by cheating, Moran murdered Adair to prevent him revealing this information to the Duke and banning him from the club, which would lose Moran his main source of income.
- Lord Balmoral may have been a coded reference to Edward, Prince of Wales, who was involved in a high-profile gambling scandal in 1890.