Like the origin of the Senas, their early history or circumstances, which led them to concentrate in Bengal is also still unknown. It has been presumed by historians that the Senas came to Bengal on the eve of the invading army led by the Chalukya kings Vikramaditya VI and Someswara III. Some scholars have also suggested that when Rajendra Chola's army had invaded Bengal, the Senas had accompanied them. According to some other historians, a few Karnataka officials, who were subordinate to the Pala kings, had established their independent kingdom in the region of Radha, taking advantage of the weakness of the Pala powers. Those Karnataka chiefs might have arrived in Bengal in wake of the Chalukya invasion and had settled into a kingdom of their own. According to historians Samantasena was such a chief who had established his independent kingdom in the Radha region of Bengal.