When William Edgar first came to London he had a haberdashery stall at St. James's Market in Haymarket. With no lodgings to go to, used to sleep under it at night. He met Mr. Swan, a draper about whom very little is known, and together they opened a shop in the Ludgate area of the City. The business did tolerably well and in 1812-1814 the friends were able to move out of the City to 20 Piccadilly. Following the construction of Regent Street, they moved into number 49, which had been the premises of the Western Mail and Coach Offices and also of the Bull & Mouth inn, (the licence for which they retained until shortly before it closed in the late 20th century).

Mr. Swan died in 1821, but Edgar retained his name, even after the refurbishment and the erection of the splendid new shop-front in 1841. Mr. Edgar flourished and was a familiar sight riding his horse to work from his home at Kingston Hill. He was always asked to be on hand to personally help when Queen Victoria's family visited the store. Expansion meant that, by 1848, the business had come to occupy the premises at numbers 45-51 on the Quadrant and the entire corner of Piccadilly circus. The shop-front was one of the West End businesses targeted by the Suffragettes in their window-breaking spree on November 21, 1911.

The premises were rebuilt and integrated in 1910-20 to a design by Sir Reginald Blomfield and became a popular place of assignation for Londoners for many generations. The store was hit by the last Zeppelin raid on London in 1917. The business was taken over by the Drapery Trust in 1927 and later by the Debenham Group, which closed it in 1982 because, they claimed, it would cost too much to modernize it. and until recently it was the flagship UK store for Tower Records. It was bought by Richard Branson of the Virgin Group in 2003 and it is now a Virgin Records Megastore.