Darker was born at Stoughton in Leicestershire, but by 1749 his father was established as a hop-merchant in Clerkenwell. Darker himself appears to have joined the firm shortly afterwards and remained in business till about 1773, building up a fortune and acquiring considerable property in Northamptonshire and Leicestershire.
In 1766 he successfully contested Leicester on the corporation interest.
In 1768 Darker again stood at Leicester as a corporation candidate, but was defeated after a fierce contest. In 1774 and 1780 he was returned unopposed on a compromise between the corporation and the independent interest.
Darker, writes Nichols,
He died 8 Feb. 1784.
