At its height in the early 9th century, the Pala Empire was the dominant power in the northern Indian subcontinent, with its territory stretching across the Gangetic plain to include parts of modern-day eastern Pakistan, northern and northeastern India, Nepal and Bangladesh. The empire reached its peak under Emperors Dharmapala and Devapala. The Palas also exerted a strong cultural influence under Atisa in Tibet, as well as in Southeast Asia. Pala control of North India was ultimately ephemeral, as they struggled with the Gurjara-Pratiharas and the Rashtrakutas for the control of Kannauj and were defeated. After a short lived decline, Emperor Mahipala I defended imperial bastions in Bengal and Bihar against South Indian Chola invasions. Emperor Ramapala was the last strong Pala ruler, who gained control of Kamarupa and Kalinga. The empire was considerably weakened by the 11th century, with many areas engulfed in rebellion.