John Lockwood was apprenticed to John Burgin, becoming a Freeman with Hallamshire Company of Cutlers in 1767, when he was assigned the 'CX' mark. He had two sons, John Jnr and William. In 1803, already trading in Arundel Street, William married Ann Sorby, daughter of Thomas Sorby of Sheffield tool-makers Sorby, Hobson & Co. The 'Lockwood Brothers were the four sons of William and Ann - William, John, Joseph and Charles.
By 1837, Lockwood Bros were listed in Arundel Street and partnered by John Sorby & Sons in Spital Hill (at the opposite end of the city). The partnership was dissolved in 1844, with Lockwood Bros acquiring the Sorby marks and business. By 1861, the company claimed to employ 500 hands. In 1865, they further expanded their Arundel Street premises, and leased a portion of the nearby works of W & S Butcher, which still stands as Sterling Works (I should have a photo somewhere).
German counterfeiting of Lockwood knives caused the company to adopt the famous Pampas Rhea mark, with the words 'Pampa' and 'Real Knife' (a phrase which was used by other Sheffield cutlers). The main trade mark was 'C:X'. They also acquired other marks.
Three of the Lockwood Brothers died in the 1870's, but the firm remained one of Sheffield's leading tool and cutlery firms. In 1881, they employed 400 workers. A decade later, they moved to the old Sorby premises, and became a limited company (I recently posted photos of the Sorby premises as it stands today).
By WW1, Lockwood's were in decline, and in 1919, the firm became part of the Sheffield Cutlery Manufacturers Ltd, a group led by Needham, Neall, & Tyzack. This venture did not fare well though, and by 1927, Lockwood's marks and assets had been acquired by Joseph Elliot, who ran Lockwood Brothers as a stand-alone brand from their Sylvester Works.. Elliot's was wound up in 1998.