During the 16th century, Habsburg Spain saw a steady growth in its military power. The Italian Wars (1494–1559) resulted in an ultimate Spanish victory and hegemony in northern Italy by expelling the French. During the war, the Spanish army transformed its organization and tactics, evolving from a primarily pike and halberd wielding force into the first pike and shot formation of arquebusiers and pikemen, known as the colunella. During the 16th century this formation evolved into the tercio infantry formation. The new formation and battle tactics were developed because of Spain's inability to field sufficient cavalry forces to face the heavy French cavalry. Habsburg Spain came to enjoy an axis of allied and neutral territories from Naples through Milan and northwards to the Netherlands, a route for reinforcements that came to be called the Spanish Road. Backed by the financial resources drawn from the Americas, Spain could afford to mount lengthy campaigns against her enemies, such as the long running Dutch revolt (1568–1609), defending Christian Europe from Ottoman raids and invasions, supporting the Catholic cause in the French civil wars and fighting, England during the Anglo-Spanish War (1585–1604). The Spanish army grew in size from around 20,000 in the 1470s, to around 300,000 by the 1630s during the Thirty Years' War that tore Europe apart, requiring the recruitment of soldiers from across Europe. With such numbers involved, Spain had trouble funding the war efforts on so many fronts. The non-payment of troops led to many mutinies and events such as the Sack of Antwerp (1576), when unpaid tercio units looted the Dutch city.