"Costanzo da Ferrara (1450–1524) was an Italian painter and medalist, born in Ferrara, but working mainly in Naples.
Costanzo was asked to go to Istanbul, capital of the Ottoman Empire, to make a portrait of the sultan Mehmet II. Diplomatic relations were restored with the Ottoman Empire after the Ottoman offensive on Negroponte in 1470. At that point, the sultan asked for "uno pittore de quelli dal canto di qua" (a painter from over here). Ferdinand I of Naples (1423–1494), recognizing the Ottoman ruler, commissioned the work.
Costanzo da Ferrara probably resided in Istanbul during the period 1475 to 1478, and may have remained there until the death of the Sultan in 1481. Two medals were minted in the name of the Sultan, one with "Asie et Gretie imperator", the other with "Bizantii imperator"." - (Wikipedia (en) 05.06.2021)
en
)