Lambton County started as a part of the District of Hesse. The district of Hesse included British territories west of Long Point (practically all of western Ontario). The district was later divided and renamed using English district names (Essex, Suffolk, Kent, etc.). Lambton was part of Kent county. In 1849 districts were abolished and the County of Lambton was formed. Lambton and Kent first shared the capital city of Sandwich (since renamed as Windsor, Ontario). In 1852 the partnership was dissolved and Lambton become a full county. It is named in honour of John Lambton, 1st Earl of Durham, who visited the area in the late 1830s.