The firm originally brewed stout and strong export ales. By the mid-19th century J&R Tennent was the world's largest bottled beer exporter. Robert Tennent died in 1826 and John Tennent in 1827. Hugh Tennent (the eldest son of Robert) then assumed control of the business. Hugh Tennent retired in 1855 with his fifth son, Charles Tennent, taking over, but he died in 1864, some months before his father. The brewery was subsequently operated by trustees on behalf of Charles Tennent's sons, Archibald and Hugh.