Yuzbak Khan's invasion of Kamarupa

Malik Ikhtiyaruddin Yuzbak invaded Kamarupa and initially gained some success. However he was later defeated and taken prisoner by kamrup soldiers.

Background
In 1228, Raja Prithu of Kamrup was killed by Malik-us-said Nasir-ud-din Mahmud Shah and his son was placed on the throne on the condition of paying tributes. In 1229, Nasir-ud-din, the governer of Bengal died, Raja Sandhya of Kamata Kingdom drove away muslims from the country and brought the regions up to Karatoya under his control. Next, Raja Sandhya invaded Gaur and with the support of several hindu chiefs of Kamrup called Bhuyans, annexed trans-karatoya regions without any strong resistance from the muslims. Thus, Sandhya avenged the previous loss of Kamrup the hands of muslim invaders and assumed the title of "Gaudesvara".

Battle
Malik Yuzbek was determined to invade Kamrup to avenge the previous loss. According to Jadunath Sarkar, Yuzbek crossed river Karatoya near Goraghat in Rangpur district and marched through modern Goalpora district. Yuzbek invaded "Kamrud" which was no other than present Gauhati or its immediate vicinity. This was called Kamarupa Nagara by pala kings. Yuzbek occupied Kamrud and got immense wealth and treasures. Yuzbek's army did not meet much resistance while advancing but they got effective resistance from the rear. Invaders first occupied the capital and Rai of Kamrup evacuated it. But the muslims could not get full possession of the city as they were engaged in fierce fighting with kamrup soldiers who were armed with bows and arrows.

As the monsoon arrived, kamrup soldiers arrived from all sides, cut off the supplies of the city and seized plains and waterways. The Sultan caught hold of a guide who undertook to conduct his army by a shorter route through the submontane tract, evidently by way of Cooch-Behar and Jalpaiguri, in the direction of Devkot. When the Sultan had retreated several stages, and entered the defiles and jungles he was trapped in a narrow valley assailed by the Hindus on all sides. In an engagement there, the entire Turkish army was defeated and killed and the Sultan with all his children, family and dependents became captives in the hands of Sandhya.

Aftermath
Due to wounds, Yuzbak died in front in his son. To check the further invasion of the Muslims, Sandhya shifted his capital from north Gauhati to Kamatapur.This place had more strategic importance than the old city. From now onward the Kingdom of Kamarupa isas called 'Kamata' and the king designated as 'Kamatesvar.'