Alaeddin Keykubad I
Alaeddin Keykubad was one of the most successful sultans of the Seljuk Empire. After the death of his father, sultan Giyaseddin Keyhusrev I, Alaeddin's brother Izzeddin Keykavus I ascended to throne. Alaeddin fought against his brother to become the sultan but he lost the battle and was put in prison. When Izzeddin died in 1220, since he didn't have any sons, Alaeddin ascended to throne and ruled the Empire between 1221-1237. He was born in 1188 or 1190 and died in 1237.
Most of buildings he ordered during his rule can still be seen today in Anatolia, such as Alaeddin mosque in the center of Konya, fortress of Nigde, Yivli (fluted) minaret mosque in Antalya, Kubad-Abad palace in Beysehir, Sultanhan caravanserai in Aksaray are some of them.
He brought Seljuk Empire to its heydays during his rule, giving a great importance to trade and science. Antalya and Sinop became important ports to extend empire's boundaries and navy fleet, and develop the commerce. He invited many intellectuals and artists to his court, including Mevlana Rumi.
Alaeddin Keykubad died on 31st May 1237 in Kayseri during a feast in honor of foreign ambassadors. There were rumors that his son, Giyaseddin Keyhusrev II, poisoned him in order to become the next sultan earlier than expected. He's buried in Alaeddin mosque in the city of Konya.