South-west terrace of Belgrave Square (C) Stephen Richards The south-west terrace was built some time between 1826 and 1837. Each of Belgrave Square's four terraces was designed by George Basevi, and its three corner mansions, an unusual device, were designed by separate architects. Each terrace has emphases at its ends and in the middle, making it resemble the facade of a palace. Grade I listed.
It is a very grand square, covering some ten acres, lent a coherence by the terraces (although they are subtly different) and the landlord's continuing restrictions on decoration (any colour you like as long as it's cream). The generally greater embellishment (e.g. heavier cornices) is typical of the age, as late Georgian transmuted into Italianate. Comparison with a mid-Georgian square such as Bedford Square is instructive <a href='http://www.geograph.org.uk/photo/562542'>TQ2981 : South Side of Bedford Square</a>.
Much of Belgravia was developed in the 1820s, having previously been a rural area renowned for its footpads and robbers ('a dreary tract of stunted, dusty, trodden grass, beloved by bull-baiters, badger-drawers, and dog-fighters'). It was, and still is, owned by the Grosvenor family, the Dukes of Westminster, whose main builder was Thomas Cubitt (reputed to have done 'more to change the face of London than any other man'). It was unpromising land on which to build because of its clay which retained water and left the area resembling a swamp ('lagoon of the Thames'). The determined Cubitt kept digging until he met gravel, burned the clay to make bricks, and he was away. It soon proved a profitable development, helped in part by George IV's decision to convert nearby Buckingham House into his residence.