Explanation:

 Iban-Batutah who visited Bengal during 1346-47 A.D. wrote in his narratives account that he came to the "Mountain of Kamru''' to visit  saint Jalal Uddin Tabrizi. It is now recognised by historians that this Jalal Uddin was no other than the famous Shah Jalal of Sylhet who died about 1346 A.D., shortly after Ibn-Batuta visited Assam. It will appear therefore that the Country to the east of MymenSingh was called "Kamru" irrespective to the territories, actually within the Kingdom of Kamrupa.