The fifth Earl of Haddington, Charles, was married to a woman who held the Earldom Of Rothes . The couple decided that it would be best to keep the titles separate; therefore, it was decided that the earldom of Rothes would go to their eldest son, while the earldom of Haddington would go to their younger son, from whom all future Earls of Haddington have descended.
The only subsidiary title held by the Earl is ''Lord Binning and Byres'' (created 1613), which is the Courtesy Title for the eldest son of the Earl.
