The Eighty Years' War began with a series of battles mostly fought by mercenaries, as was typical of the time. While successes for both parties were limited, costs were high and continued to grow as the war progressed. The structural inability of the Spanish government to pay its soldiers—it went bankrupt several times—led to perpetual large-scale mutinies among the Spanish army in the Netherlands, which continually frustrated Spain's military campaigns in multiple fronts while at the same time defending a huge colonial empire. On the Dutch side the States of Holland, with its opulent capital Amsterdam, bore the brunt of the costs of war and were able to do so successfully as locals. The Spanish effort in the Netherlands was also hampered by the war against the Ottoman Empire in the Mediterranean during the 1570s, which demanded much of Spain's financial and human resources.