It was created in 1922 for Conservative politician Arthur Balfour, Prime Minister of the United Kingdom from 1902 to 1905 and Foreign Secretary from 1916 to 1919.

[1] The earldom was created with special remainder, failing male issue of his own, to: The latter two were the sons of his deceased youngest brother Colonel Eustace James Anthony Balfour.

Balfour was made Viscount Traprain, of Whittingehame in the County of Haddington, at the same time as he was given the earldom.

[1] Balfour never married, and was succeeded according to the special remainders by his younger brother Gerald, the second Earl.

He is the grandson of the aforementioned Francis Cecil Campbell Balfour, nephew of the first Earl.