Giyaseddin Keyhusrev (1204-1211)
Due to the very young age of his son, Kilic Arslan III who replaced him, the Danismendli beys who were in the service of the Seljuk State collaborated with the Emir Mubarizeddin Ertokus. Then, they invited Giyaseddin Keyhusrev who was still in Istanbul for the enthronement in Konya. Meanwhile, Istanbul was invaded by the Latins and the Byzantine empire was divided into pieces. Giyaseddin Keyhusrev advanced towards Konya together with the troops that he had conscripted from the Turkmens in the forefront places. Pursuant to a blockade that lasted for one month, Giyaseddin Keyhusrev captured the city and he ascended the throne of the Seljuk State for the second time (February 1205). Sultan Giyaseddin Keyhusrev established the peace and security within a short period and then, he made an agreement with the emperor of Iznik, Theodoros Laskaris. Afterwards, he organised a military expedition against the Trebizond Komnenos family that threatened the trade route of the Black Sea and tried to settle on these coasts. In this expedition that was carried out in the year of 126, Aleksios Komnenos was defeated and the trade route of the Black Sea that was closed for a specific period was opened again. Giyaseddin Keyhusrev appreciated the conditions of the countries in respect of the trade and economy and he followed an appropriate policy in this regard. Pursuant to his expedition to the Black Sea, he besieged Adalia (Antalya) as the leader of his army in person. Antalya that was an important port for importation and exportation in Anatolia was under the domination of an Italian named as Aldo Bardini in that period. However, upon the help and support provided from Cyprus, sultan could not capture the city. Nevertheless, a military expedition was organised against Leon II, the Armenian king of Cilicia who tried to benefit from the changes in the throne of the Seljuk State and this expedition resulted with victory and the places invaded by him were recaptured (1209). This victory was followed by the prevention of Eyyubi State from its activities in the Northern Syria and Anatolia.
The victories that Giyaseddin Keyhusrev won in the coasts of the Black Sea, the Mediterranean Sea and against the Armenians caused discord between him and Theodoros Laskiris who was the emperor of Iznik. On the other hand, the strengthening of Laskaris made the Selkuk sultan suspicious about him. The foreign provocation and the non-payment of the annual tax by the emperor led Giyaseddin Keyhusrev to organise a military expedition against the emperor of Iznik. While Sultan set off with his army, he took Aleksior, the former emperor with him; he wanted to enthrone him again as he emperor. The two armies encountered in the border of Alasehir. Sultan Giyaseddin Keyhusrev was killed as a martyr in the war between the two sides and the Seljuk army was defeated (1211).