The Truce of Constantinople (Turkish: İstanbul antlaşması) was signed on 22 July 1533 in Constantinople by the Ottoman Empire and the Archduchy of Austria after the Habsburg–Ottoman war of 1529–1533.
According to several sources, this and other ceasefire agreements produced in 1547, 1568, 1573, 1576, 1584 and 1591 were truces or armistices (with a limited period of mutual non-aggression) and not treaties, as no real peace treaty was concluded in the entire sixteenth century.[1][2][3] Gábor Ágoston calls this a treaty or truce, but defines its nature as mere "verbal promise" (correspondences between Ferdinand and his envoy also show the agreement as a matter between Suleyman and the king).[4] Mortimer also states the truce was between Ferdinand and Suleyman. Only the 1547 truce received endorsement from Charles V.[5]