Monmouth Street was the name of a street cleared away in 1889 when Shaftesbury Avenue was cut through along the north-west side of Seven Dials as a combined work of slum clearance and traffic improvement. The name was reassigned in 1938 to two streets then known as Great St Andrew’s Street (from The Dials northwards to Shaftesbury Avenue) and Little St Andrew’s Street (from The Dials southwards to Upper St Martin’s Lane). In 1924, to ease lorry traffic congestion around Covent Garden Market, this section became one of the first roads in London to be made one-way.