Funded through public subscription, the New Assembly Rooms in Edinburgh were centrally located on George Street in the Georgian era New Town.
New Town was “designed to house the wealthy and attract back to Scotland the absentee noblemen who now lived in London” with luxury retail, fine new houses, symmetrical streets, and open squares (BBC – History – British History in depth: The Rise of Edinburgh). This investment would see dividends with a boom in the financial industry, including the formation of many new banks to support industrialization. The New Assembly Rooms were a continuation of the seduction of London aristocrats, and once completed in the beginning of the 19th Century demonstrated an elegance thought to “exceed that of the Great Room in Bath” (Edinburgh’s Assembly Rooms: A Potted History | EdinburghGuide.com).
In August 1822 the Assembly Rooms hosted ‘The Peers Ball’, which marked the occasion of King George IV’s visit to Edinburgh.
Eyewitnesses recounted a crowd gathered outside to watch the traffic descend upon George Street and the arrival of King George; “…the sudden rush of carriages, the roaring of coachmen and the impatient objurations of the Highland [sedan] chairmen, enforced by the furious driving of their poles, threatened more than once to shake the democracy from its propriety!”
The ton of Edinburgh arrived for the Peers Ball in their finest toggery: “The ladies were in most elegant white dresses, richly bespangled and had on plumes of white ostrich feathers, their plumage in constant undulation, appearing to the eye like an ocean of foam”. The men meanwhile had either opted for formal court dress, or had taken the opportunity to wear tartan, which was newly fashionable during the King’s visit. Other noblemen and gentlemen gaily disported themselves in the mountain garb.”
Here is one account of an early 19th century visitor to the Assembly Rooms:
Caledonian Sketches, Or, A Tour Through Scotland in 1807 (1809)
Read about some of the rules for the New Assembly Rooms on this site: https://www.regencydances.org/paper025.php#edinburgh