In 1753, Giovanni Battista Torre, a pyrotechnist, arrived in London. Four years later, he opened a shop in Paris for the sale of scientific instruments and books, "Cabinet de Physique Expérimentale". Torre opened a small branch of this shop near Pall Mall, London, in 1767. The firm began a connection with an engraver of colored stipple prints, named Bartolozzi. In 1780, G.B. Torre died, and his son, Anthony, formed a company with Ciceri, a Milanese optician; the partnership was dissolved in 1782, however.
Around 1783, Paul Colnaghi came under the employ of Ciceri. By 1784, Colnaghi was acting as an agent in Paris, with a shop in the Palais Royal, to sell English prints for Anthony Torre. The next year, Colnaghi joined Torre in London, working from a shop on Market Lane; in 1786 they moved the shop to 132 Pall Mall. Colnaghi published a popular colored stipple-print series entitled The Cries of London from 1792-97. The shop moved again, to 23 Cockspur Street, in 1799. Around this time Colnaghi was appointed the print-seller to the Prince Regent, and later, to King George IV. Other royal customers included the Duke of Orléans (later King Louis-Philippe).
Colnaghi's sons Martin and Dominic became active in the firm around 1810. Martin's share was eventually bought out for 3000£, after which Paul and Dominic re-opened a shop at 14 Pall Mall East. In 1851, Martin Colnaghi died. Some time between then and 1864, Dominic died at the age of eighty-nine. In 1864, Dominic's nephew (who played some role in the firm) John Anthony Scott died, and his cousin, Andrew McKay, became sole proprietor of Paul and Dominic Colnaghi & Company. McKay's son William joined his father in the firm in 1879, and was in charge by 1894, when he took E.F. Deprez and O.C.H. Gutekunst into the partnership. Deprez retired in 1907; Martin Colnaghi, Jr., who had carried on Martin's separate business at 53 Pall Mall, died in 1908.
William McKay retired in 1911, the year that Gustavus Mayer, formerly of Obach and Company (168 New Bond Street), joined the firm. The official name of the firm became Messrs. P. & D. Colnaghi and Obach. In 1912, they moved to a new building designed by Lanchester and Rickards at 144-6 New Bond Street. Four years later the name of the firm was changed back to P. and D. Colnaghi and Company. In 1937, the firm became a Limited company with three directors: O.C.H. Gutekunst, G. Mayer, and J. Byam Shaw. Two additional directors were added in 1939--H.J.L. Wright and D.C. Baskett--while Gutekunst retired. The latter died in 1947; Mayer died in 1954. In 1955, a new director was added, R.M.D. Thesiger.