Muslim armies had also moved north of the Pyrenees but they were defeated by Frankish forces at the Battle of Poitiers, Frankia and pushed out of the very southernmost region of France along the seacoast by the 760s. Later, Frankish forces established Christian counties on the southern side of the Pyrenees. These areas were to grow into the kingdoms of Navarre and Aragon. For several centuries, the fluctuating frontier between the Muslim and Christian controlled areas of Iberia was along the Ebro and Douro valleys.