Montagu Square is in Marylebone, London. It is situated a little north of Marble Arch, between Edgware Road and Marylebone High Street.
It was built as part of the Portman Estate between 1810 and 1815, and first leased to the builder David Porter. Mr Porter had started life as a chimney sweep and named the square after his former benefactor, Elizabeth Montagu. Mr Porter was rescued by Lady Montagu when she recognised him as one of the children of an acquaintance. Thereafter she held annual parties for chimney sweeps.
Mrs Montagu was in the rare position of having inherited a large sum when her husband died and had Montagu House constructed on the site of modern day Portman Towers. The carriage drive led onto Portman Square and Montagu House was said to be the second grandest house in London.
It was damaged by bombing in WW2 and could have been repaired, but was demolished in the 1950s.
The handsome portico has been installed as the back entrance to Kenwood House.
Montagu Square Garden is a private garden and not accessible to the general public. Please also note that CCTV is in operation the garden.