The Battle of Roncevaux Pass ( French and English spelling , `` Roncesvalles `` in Spanish , `` Orreaga `` in Basque ) in 778 saw a large force of Basques ambush a part of Charlemagne 's army in Roncevaux Pass , a high mountain pass in the Pyrenees on the present border between France and Spain , after his invasion of the Iberian Peninsula .