From 1526 to 1606, the Habsburg Ottoman contest for control of Hungary dominated the external affairs of central Europe. This was not simply a religious war in Germany, Catholics and Protestants were at times fighting each other. But in the period covered here (1540 1580) no European state could withstand the sultan s armies. Austria s Protestant nobles commanded the forces of their Catholic sovereigns. and in the Holy Roman Empire, after 1555, Protestant and Catholic estates joined against a common threat. Historian James Tracy explores the relative strengths of forces, Habsburg military strategies, and the futility of negotiating from a position of weakness. As composite states, the Habsburg Monarchy and the Holy Roman Empire are not thought to have functioned well, yet both showed a surprising resilience.