Thomas Mercer, the founder of the firm Thomas Mercer Ltd, was born in Lancashire in 1822. After his death in 1900 the business was continued by his sons Thomas (1876-1935) and Frank (1882-1970). Under their management the company continued to make the chronometers which had been the core of their business in the 19th Century but also diversified into other areas of clockmaking. The firm subsequently passed into the hands of Frank's sons, Thomas Gurney and Frank Anthony. In 1984 it was purchased by the company Sinclair Harding.