The delay and practical defeat sustained at Güns, together with the defeat of another Turkish army which was to enter Austria by the Semmering Pass proved the saving of Vienna. Suleiman had announced that he did not intend to attack Vienna on this campaign; nevertheless his vast preparation and the counter‐preparations of Charles V and of Germany suggested a more ambitious campaign than that which he carried out. In any case Suleiman decided to withdraw, and immediately after investing Gratz, which was well defended, he abandoned the enterprise and returned to the Porte. When the Sultan made peace with Ferdinand in 1533, and temporarily ceased operations on his northern frontier, he turned his attention to conquests in two other directions, namely to the extension of his sea power, and to the reduction of Persia. The romantic story of the exploits of his great admiral Khaireddin Barbarosa does not come into our field, but the Persian campaign is the next object of our attention. Ever since Suleiman’s accession to the throne the relations of the Porte with the Shah of Persia had been strained. The only reason that this had not resulted in open war was because Suleiman was more deeply concerned in Hungarian affairs. There was continual fighting on the frontier. When Shah Tahmasp succeeded his father Ismail, he was little inclined to humble himself before the Turkish monarch, so he resented an overbearing and threatening letter from Suleiman. Now seemed a favorable moment to execute the threat of war. The excuse was the betrayal of the Ottomans by the khan of Bitlis, who had gone over to the shah of Persia, while the Persians were irate because the Persian governor of Aserbaijan and Baghdad had joined the Turks and had taken with him the keys of Baghdad. The governor having been assassinated and Baghdad retaken by the Persians, Suleiman determined on immediate war. Ibrahim, again invested with the office of serasker, was sent to Persia to retake Bitlis and Baghdad. He and his army marched as far as Konia, where he received the head of Sherefbey, after which he advanced to Aleppo to take up his winter quarters.[180] He occupied his leisure during the winter by taking several neighboring fortresses. His next plan was to move on Baghdad, but the defterdar Iskender Chelebi who accompanied the expedition urged an immediate advance to Tebriz, recently abandoned by the shah, arguing that the fall of Tebriz would mean the taking of Baghdad. Ibrahim followed Iskender’s suggestion, and arrived before Tebriz the 13th of July, 1534. Receiving the submission of many fortresses en route, he triumphantly entered the Persian capital. To avert the evils generally incident to a Turkish occupation, he set up a judge at Tebriz, and a strong guard. This was unusual self‐restraint in a Turkish conqueror. At this time he suffered the loss of one of his armies in the defile of Kiseljedagh, but otherwise he met only with victory and submission.