Arriving in Constantinople towards the end of 1332 (or 1334), he met the Byzantine emperor Andronikos III Palaiologos. He visited the great church of Hagia Sophia and spoke with an Eastern Orthodox priest about his travels in the city of Jerusalem. After a month in the city, Ibn Battuta returned to Astrakhan, then arrived in the capital city Sarai al-Jadid and reported the accounts of his travels to Sultan Öz Beg Khan (r. 1313-1341). Then he continued past the Caspian and Aral Seas to Bukhara and Samarkand, where he visited the court of another Mongolian king, Tarmashirin (r. 1331-1334) of the Chagatai Khanate. From there, he journeyed south to Afghanistan, then crossed into India via the mountain passes of the Hindu Kush. In the Rihla, he mentions these mountains and the history of the range in slave trading. He wrote,