Rome's alliance with the Aetolian League in 211 BC effectively neutralised Philip's advantage on land. The intervention of Attalus I of Pergamum on the Roman side further exposed Philip's position in Macedonia. Philip was able to take advantage of the withdrawal of Attalus from the Greek mainland in 207 BC, along with Roman inactivity and the increasing role of Philopoemen, the strategos of the Achaean League. Philip and his troops sacked Thermum, the religious and political centre of Aetolia. His troops destroyed 2,000 statues and hauled away vast sums of treasure which included some fifteen thousand shields and suits of arms the Aetolians had decorated their stoas with. These shields were the armor taken from the enemies of the Aetolians during their previous military victories and included the shields of the Gauls who had raided Greece in the 3rd century BC.