Shiva Purana
पुरा सुदक्षिणां तत्र कामरूपेश्वरं प्रभुम् ॥ जेतुं गतस्ततस्तेन युद्धमासीद्भयंकरम् ॥ ३६ ॥
At first he went to conquer Sudakṣiṇa, the king of Kāmarūpa. Then he fought a terrible battle with him.
english translation
purA sudakSiNAM tatra kAmarUpezvaraM prabhum ॥ jetuM gatastatastena yuddhamAsIdbhayaMkaram ॥ 36 ॥
hk transliteration by Sanscript