Cavendish Square Gardens

Cavendish Square was built in 1717 and named after the Duke of Portland's great grandmother.

The Duke of Portland was Prime Minister when Norrell arrived in London, though he retired in 1809 and died shortly after. He was succeeded by Spencer Percival, who was assassinated in 1812; after that Lord Liverpool became the PM until 1827.

The Duke of Portland's full name is William Henry Cavendish Cavendish-Bentinck, 3rd Duke of Portland, which is nicely mental. Many of the street names in the area around the Portland Estate come from this family, including Harley Street and Oxford Street.