John Blackett was High Sheriff of Northumberland in 1692, He married Mary, daughter and heir of Richard Errington.
In 1685 he acquired two farms at Wylam, Northumberland, and the Manor estate including the mineral rights, from the exploitation of which the family was to benefit greatly.
John Blackett (1712-1769), his son, High Sheriff in 1738, sold the families Co Durham properties and established coal mining and Wylam Colliery in the township in the mid 18th century.
The family were keenly involved in the development of steam power for the improvement of coal transportation.
William Hedley, Timothy Hackworth and Jonathan Forster all worked at Wylam Colliery for Christopher Blackett (1751-1829), and there produced the famous early steam locomotives Puffing Billy (1813-1814) and Wylam Dilly (1815) History of the Commoners of Great Britain and Ireland (1835) John Burke.