Rukunuddin Kaikaus ruled Bengal in 1291-1300 CE. In 1291 he succeeded his father Nasiruddin Bughra Khan as an independent ruler of Bengal.[1] In several inscriptions and coins he styled himself as Sultan-bin-Sultan (the Sultan, son of a Sultan) and also Sultan-us-Salatin (the Sultan of Sultans).[2]
During his reign, he had divided his kingdom into two parts - Bihar and Lakhnauti. He appointed Ikhtiyaruddin Firoz Itgin as the Governor of Bihar and Shahabuddin Zafar Khan Bahram Itgin as the Governor of Lakhnauti. Zafar Khan Itgin conquered Satgaon in south-western Bengal. Thats how his kingdom extended to Bihar in the west, Devkot in the north and Satgaon in the south. He put a vast kingdom under his control. Delhi Sultan Alauddin Khilji also accepted Kaikaus's independent dominance of Bengal.[2]
Rukunuddin Kaikaus ruled Bengal for nine years and died in 1300.