Early August 1644 saw the two greatest French men-of-war of the mid-seventeenth century, Turenne and the future Grand Conde, attempt to dislodge the Bavarian general Franz von Mercy from the heights of Freiburg in the Black Forest. In the twilight of the Thirty Years' War, there was probably no better opponent for these two geniuses than Mercy, who had the astonishing ability to anticipate his enemies' plans. Against such a general, it would take no less than Enghien and Turenne. The battles of 3 and 5 August were among the most difficult that the two men would face throughout their careers: their carefully prepared plans were thwarted by the shrewdness of their opponents and some unfortunate initiatives on the part of their subordinates. The battles were so deadly that they brought Mazarin to tears. On learning of what could be considered a victory, the Cardinal is said to have stated that France would have been lost if it had won many similar victories. The days of Freiburg were the setting for some fascinating actions in which doggedness gave way only to courage. Thanks to numerous contemporary accounts, the reader is immersed in the heart of the two battles that enabled the French, despite being held at bay, to keep the Bavarians away from the right bank of the Rhine. The context of the campaign, the character of the three protagonists, the phases of the various battles, the armies involved and the lessons learned are all analysed in detail. 45 b/w illustrations, 24 colour illustrations/figures, 7 colour maps