Plaque

On the map of 1862, when this area was first developed, it looks as easy to travel north-south on what is now Rutland Gate/Rutland Street as on Montpelier Walk, so we did some investigation. 

The Survey of London has answers:  “During the next six years {1853 – 9} the whole of southern Rutland Gate was built up by Elger, together with Rutland Mews East and West and a roadway linking Rutland Gate with his development on the Kingston House estate {to the west}.  It was presumably at this time that the high brick wall along the south side of Ennismore Street was built, shutting off Brompton Road and its northern hinterland from the exclusive culs-de-sac opposite Hyde Park. Since the Second World War a footway has been opened between Rutland Mews East and Rutland Street, which goes some way to alleviating the isolation of Rutland Gate from Brompton Road and the area of Montpelier Square.”

So the wall was deliberately created to create/maintain a physical class separation.