Now containing some of the finest houses in London, Hanover-square was first built around 1720 and named in honour of the new king George I. (His Majesty, who was a German by birth, had prior to his accession to the British throne been the Prince-elector of Hanover). Its first tenants were of the military order - generals and the like - but despite the splendour of its mansions there was a period, some thirty years before the renowned magician Gilbert Norrell took up his residence there, when the square had fallen rather on hard times. (A gentleman in 1771 actually complained that "the middle has the air of a cow-yard, where blackguards assemble in the winter to play at hustle-cap, up to the ankles in dirt.") [see further]
Happily the convenience of the site, its nearness both to Oxford-road and to the church of St. George, scene of so many fashionable marriages, persuaded the inhabitants to undertake improvements. It is now among the most desirable addresses in the capital. It is small surprise that John Childermass advised Mr. Norrell to take a house there if he wished to cut a respectable figure in London society.
Hanover-square was also the place where Lady Pole made her unfortunate attempt on Mr. Norrell's life.