1. Kayqubad I expanded the borders of the sultanate at the expense of his neighbors, particularly the Mengujek Beylik and the Ayyubids, and established a Seljuq presence on the Mediterranean with his acquisition of the port of Kalon Oros, later renamed Ala'iyya in his honor.
Kayqubad I's reign represented the apogee of Seljuq power and influence in Anatolia, and Kayqubad I himself was considered the most illustrious prince of the dynasty.
Kayqubad I was the second son of Seljuk Sultan Kaykhusraw, who bestowed upon him at an early age the title malik and the governorship of the important central Anatolian town of Tokat.
Kayqubad I was forced to flee to the fortress at Ankara, where he sought aid from the Turkman tribes of Kastamonu.
Kayqubad I was apprehended and imprisoned by his brother in a fortress in western Anatolia.
Kayqubad I attacked the Armenian Kingdom of Cilicia in 1221 taking the city of Alanya from its governor, Kir Fard.
In 1234 Kayqubad I completely defeated the allied Ayyubid forces.
Kayqubad I put down a revolt by the Empire of Trebizond and, although he fell short of capturing their capital, forced the Komnenos dynasty family to renew their pledges of vassalage.
At first, Kayqubad I sought an alliance with his Turkish kinsman Jalal ad-Din Mingburni against the Mongol threat.
Kayqubad I had three sons: Kaykhusraw II, eldest son of his Greek wife Mah Pari Khatun, Rukn al-Din and Kilic Arslan, sons of his Ayyubid princess wife Malika Adila Khatun.
Kayqubad I had good relations with the Muslim scholars, Sufis and poets.