Frieze Masters usually belongs to the brand-name artists. This year one of the week's most talked-about offerings is something far stranger: more than 10,000 satirical prints and drawings, assembled over a lifetime by the late Soho restaurateur and print dealer Andrew Edmunds, on sale as a single lot for £12 million.

The collection is being presented by dealer Daniel Crouch, who describes it as one of the great social and political collections of its kind. Mostly comprising 18th- and 19th-century satirical prints by William Hogarth, James Gillray and Thomas Rowlandson, it represents what curators and dealers consider an esoteric trove beside the headline-grabbing modern and Old Master material that dominates the fair. Crouch is refusing to break the collection up for individual buyers.

Edmunds remains best known for the eponymous dining room he opened in Soho in 1985, a candlelit restaurant that has run continuously since, even after his death. Alongside it sat his prints and drawings gallery, opened in 1974. The print collection was his private passion and lifelong obsession, and relatively little was known about its specifics until now.

Speaking about Edmunds and the sale, curator Norman Rosenthal remembered him as an extraordinary, idiosyncratic character and said the collection belongs in a museum, joking that it would take a singularly determined individual to want 10,000 prints by Hogarth and Gillray. Neighbours and friends recalled an erudite, irreverent figure who co-ran the Academy Club members' club above the restaurant.

The lot is on view in a booth dressed to resemble an 18th-century print seller's shop. For collectors priced out of the fair's blue-chip action, a postcard of Gillray's Fashionable Contrasts costs considerably less than the asking price.