In the 1820s Charles Lea became a coal merchant in London. His sons, Thomas, Charles and John followed him into the family business to form Lea & Sons.
In 1836 Charles Lea retired and dissolved the partnership with his sons. Each of the sons then went into business for himself as a coal merchant.
The 1841 the London Post Office Directory listed the business address of Thomas Lea & Co., coal merchants, as Northumberland Wharf, Augustus Street, Regents Park Basin.
Thomas Lea lived in Middlesex and would drive to work in London each morning with two loaded pistols. He feared being robbed in Highgate which was the northern approach to London and still had a reputation for highway robberies at this time. Thomas Lea was never robbed and died a very wealthy man in 1874.