In 1805–06 Charles Harcourt Masters designed Cheltenham’s Royal Crescent, a seminal work within the town’s architectural history in that it was the first important terrace to grace the town at a time of rapid expansion and unprecedented popularity during the early years of the spa’s development.

In Bath and North-East Somerset Library is a plan signed by Masters for St James’s Square, Cheltenham, which though never completed was much more ambitious than Royal Crescent and possibly the largest projected square ever to grace the town. It is not dated, but it would be reasonable to assume a dating c. 1808–09 bearing in mind contemporary deeds, maps, and a newspaper advertisement to be discussed later. The earliest deeds in the possession of No. 1 St James’s Square go back only to 1856, but crucially they repeat the content of the original ones. They confirm that the square was begun in 1809 in accordance with its earliest appearance on a map called ‘Plan of The Town with the Situation of the Mineral Wells at Cheltenham’ surveyed by Daniel Trinder in 1809. He blocks in the square on three sides, excluding the south, as early as 1809, and shades in the north where No. 1 is, indicating that it was built or in the process of being built. The extent of the north side appears to be exaggerated, indicating more properties than there actually were. The deeds refer to 16 April 1808 as the date of the purchase of the land between a ‘Thomas Read of the City of Bath Esqre and a William Read of Cheltenham’, both presumably of the same family. Thomas Read’s connexion with Bath might explain in simple terms why Masters was working in Cheltenham. The 1809 date is again confirmed by the following advertisement in the Cheltenham Chronicle for Thursday, 25 May 1809: