Nasir al-Din al-Tusi
The couple was first proposed by the 13th-century Persian astronomer and mathematician Nasir al-Din al-Tusi in his 1247 "Tahrir al-Majisti (Commentary on the Almagest)" as a solution for the latitudinal motion of the inferior planets, and later used extensively as a substitute for the equant introduced over a thousand years earlier in Ptolemy's "Almagest".