Sixty years after the ballroom was completed, it was provided with a companion of equal, and perhaps less awesome, elegance. In 1806, a new dining room was designed for the corporation by William Lindley (about 1729 - 1818). A pupil of the celebrated architect, John Carr of York, Lindley had moved to Doncaster by 1783, where he carried on a thriving local architectural practice.
It seems likely that the new dining room was inspired by the wish of the corporation to present the best possible image of the town for the visit of the Prince Regent (the future George IV) and his brother, the Duke of Clarence (the future William IV) to the Doncaster races in 1806. They stayed with Lindley in his house on South Parade. Given the importance of racing to the town, it is natural that the royal visit should prompt a major improvement in the facilities available in the town's most important building. Similarly, the alterations of 1831 were specifically intended to cater for the needs of the gentry and nobility attending the races. These later alterations were the work of a pupil of Lindley, William Hurst, who was also an alderman (senior member) of the corporation.
The new dining room is, like the ballroom, sixty feet long, but is three feet lower and three feet narrower, dimensions which seem to make it a more welcoming space than the double cube room. The room as we see it now is an amalgamation of the talents of Lindley and Hurst. The inventory of 1834 refers to a new orchestra, the musician's gallery in the photograph, and in 1831, £130 was spent on the large mirror at the far end of the room and fifty guineas (£52.50p) on the two chandeliers.
Since 1914, when the council ceased to meet in the Guild Hall in Frenchgate, the dining room has been adopted as the council chamber. As we have seen, the ground floor has provided a home to council business from the beginning, and in the Mansion House of to-day, civic practicalities rather than civic pleasures dominate its daily life.