On the 27th of September Suleiman joined the grand vizir at Aoudjan and immediately rewarded him and the other beylerbeys for their successes. The united armies continued their march towards Hamadan. The lateness of the season made the crossing of the mountains very difficult. Many pack animals died and the artillery was mired in the bad roads. In that perilous situation the army was attacked by the enemy and suffered considerable loss in men and supplies. At last the army reached Baghdad. The governor sent a letter of submission, and then to secure his own safety, fled. The grand vizir immediately took possession of the city, shut the gates to prevent pillage, and sent the keys of the city to Suleiman who had not yet come up. Baghdad was the bulwark of the Persian empire and of great military importance. The army remained there four months while the sultan organized his new conquests. April 2nd, 1535, the Turkish army commenced its return to its capital, making a march of three months to Tebriz and thence of six months to Stambul. In this campaign Ibrahim had little actual fighting, and slight use for the artillery and mines in which he was so well versed. The success of the campaign was due to the terror excited by the reputation of the Turkish army, and the endurance with which it made terrible marches, equalling the celebrated marches of the generals of antiquity.[181] Ferdinand of Hungary wrote Ibrahim congratulating him on this successful campaign. This was Ibrahim’s last campaign. His career was cut short at this point. In this Persian expedition the grand vizir had some personal experiences which do not properly belong to an account of his generalship, but rather to the next chapter dealing with his fall.