Pal Dynasty:Who linked Bihar and Tibet
After decline of Harsh's Empire Pal Empire was founded by Gopal who was an elected King in upper Gangetic Valley form 7th century to 10th century.
Gopal defeated Pratihar who were ruler of Gaud (Bengal) and unified Gaud and Magadh
Dharmpal could not consolidate his power in north and Pratihar revived under Nagbhatt in 790.
Dharmpal got defeated in Munger but East UP (Purvanchal) remained a connection between Pal and Pratihar.
Ref-A guide to Tibet, History of Mideaval India