It was created in 1806 for Charles Agar, 1st Viscount Somerton,[2] Archbishop of Dublin.

In 1873, he was created Baron Somerton, of Somerley in the County of Southampton, in the Peerage of the United Kingdom.

[1] The first Earl of Normanton was the younger brother of James Agar, 1st Viscount Clifden and the nephew of the politician Welbore Ellis.

[6] On Lord Mendip's death in 1802, the barony passed according to the special remainder to his great-nephew the second Viscount Clifden.

The heir apparent is the present holder's eldest son Arthur Alexander Christian Welbore Ellis Agar, Viscount Somerton (b.