Smith was the son of Thomas Assheton of Ashley in Cheshire. He added "Smith" to his surname when he inherited the Vaynol and Tidworth estates from his uncle, William Smith. He was High Sheriff of Caernarfonshire in 1783-4 and Member of Parliament for the county from 1774 to 1780. Assheton Smith was also MP for the English borough of Andover between 1797 and 1821.
In 1806 he was able to get Parliament to pass an act enclosing the common land of Llanddeiniolen parish, greatly adding to his land holdings. In 1809 he took over control of slate quarrying on his estate, forming a company of four under his presidency. The company was later dissolved and he took over sole control of the enterprise. By 1826 the Dinorwic Quarry was employing 800 men and producing 20,000 tons of slate per year. Assheton Smith developed Port Dinorwic (Y Felinheli) as a port for the export of the slates.
Eglwys a Goodwyd Efo Pres Y Meistri a Gwaed Y Gweithwyr; Efallai Nad Yw'n Arbennig O Hynafol, Ond Mae Hanes Diddorol I Eglwys Llandinorwig, Fel Y Dengys Cyfrol Newydd a Gyhoeddir I Ddathlu Achlysur Arbenni
Sep 05, 2007; Byline: TUDUR HUWS JONES A R ddiwrnod glawog diflas, pan mae'r cymylau a'r tomenni llechi a'r bryniau'n un, mae Eglwys Crist...