The westward advance into Spain and North Africa occurred concurrently with conflict in the East. By 146 BC, Rome had asserted dominance over every major city on the Balkan peninsula. The subsequent century witnessed Rome's ultimate conquest of Asia Minor following a series of intricate campaigns; in the 60s, the triumphant general Pompey 'the Great' annexed Syria; in the 50s, Julius Caesar subdued Gaul (extending from the southern French Pyrenees to the Rhine); and in 31 BC, his adopted son Octavian deposed Cleopatra VII, the last independent monarch of Egypt. The most significant reward resulted from triumphing in a naval confrontation near Actium in northwest Greece. The Roman Empire now encompassed Egypt, the most ancient and affluent nation in the Mediterranean.