The nature of the Ottoman military shifted dramatically during this period. From its inception the Ottoman army was dominated by cavalry forces, with cavalry outnumbering infantry in the sixteenth century on a 3:1 or 4:1 basis. As a result of the empire's rapid expansion and the stabilization of its borders in the preceding period, as well as the increasing importance of gunpowder technology to military success, the empire adapted by widening the range of its recruitment in order to raise much larger numbers of infantry troops. By the 1690s, the infantry proportion of the field army had increased to 50–60 percent, equivalent to that of the neighboring Habsburg Empire. Calculations of total strength during this period remain unreliable, but it has been estimated that the average Ottoman army consisted of a core force of approximately 65,000–70,000 men from the timariots and standing army, joined also by irregular militias and the armies of the empire's vassals, with a particularly significant contribution coming from the Crimean Khanate. In general, the Ottoman army remained at least as effective as those of its European rivals throughout this period. In contrast with older historical views, which posited a failure to keep pace with European military developments, the Ottomans in fact demonstrated a significant degree of dynamism and a continued capacity and willingness to innovate and improve their military forces. Although the empire experienced significant defeats and territorial loss in the 1683–99 War of the Holy League, this was caused not by military inferiority, but by the size and effective coordination of the Christian coalition, as well as the logistical challenges of warfare on multiple fronts.