Its origins are controversial, as the Wellesley Arabian may be Persian, Indian, Syrian or from a country on the African continent.

One version was imported from India in August 1803 by Henry Wellesley, brother of the Duke of Wellington.

[4] Charles James Apperley (1842)[5] and Sir Humphrey Francis De Trafford (1907)[6] support this theory.

[12] Wellesley Arabian's large size suggests that he came from a region where equine food was abundant.

[4] John Scott and Thomas Brown compare it to a European military charger horse, but the limbs and thinness of the skin reveal its oriental origins.

[13][14][15] Wearing a gray coat,[10] he is reputed to have been large for his time,[4] standing 15 hands and two inches tall (1.57 m).

[22] Wellesley Arabian is therefore an exception to the rule that the Thoroughbred breed has not been influenced by foreign horses.

[7] A few of his foals were trained as racehorses, but met with too little success to be of note in the history of the Thoroughbred breed.

[28] The painting Portrait of the Grey Wellesley Arabian with his Owner and Groom in a stable was copied by Charles Turner in a fine engraving published in London by Newman on 19 August 1810.