Battle of Freiburg, 1644: Enghien and Turenne against Mercy's entrenchments

In 1643 France had broken the Spanish army at Rocroi, and peace talks had begun, but the fighting went on. In southern Germany the strongest opponent of the French was the Bavarian army of Field Marshal Franz von Mercy. In the summer of 1644, Jacob F. Field writes in Britannica, the Bavarian and imperial armies went on the offensive along the upper Rhine.²

Mercy laid siege to Freiburg im Breisgau, held for France. Adolf Schinzl, in his article on Mercy in the Allgemeine Deutsche Biographie, says he cut off the town's water on the very first day and pressed the siege so well, despite repeated attempts by Marshal Turenne to relieve it, that Freiburg surrendered at the end of July. Schinzl gives 27 July; Britannica gives 29 July.³

Two French armies

Turenne commanded the French army in Germany. To retake Freiburg he was joined by the Duke of Enghien, the victor of Rocroi. Together, Britannica writes, they had some 20,000 men, about 3,500 more than Mercy, whose cavalry was in poor condition. Mercy therefore chose to defend with his infantry, on earthworks and wooded heights south of the town.⁴

His first position lay on the hill called the Bohl near Ebringen and in the valley of the mill stream near Merzhausen. Schinzl calls it well chosen and carefully fortified.⁵

3 August: the first line

At five in the afternoon of 3 August the French made a frontal assault on Mercy's first line. By nightfall they held it, but at heavy cost, and after a stubborn fight Mercy pulled back. Because the French were exhausted, Britannica notes, he had all of 4 August to dig in again.⁶

He used it on the Lorettoberg, a hill right next to Freiburg. According to Schinzl the new entrenchments, raised in a single day, looked like the work of months.⁷

5 August: the second line

On 5 August the French attacked again. Schinzl's account, written from the Bavarian side, has Mercy reading the enemy's intentions as he had on the 3rd and directing the fight from strength, while his soldiers, spurred on by shouts of their own name, threw back French troops who fought with fury. The French held on until dusk, he says, only so as not to reveal the state of their infantry. Britannica counts 4,000 French killed or wounded that day; Schinzl puts the dead on the field at 5,000 French and 1,500 Bavarians.⁸

Among the Bavarian dead was Mercy's brother Kaspar, a general, who fell just as he turned an attack that was going badly. The two armies spent the night fifty paces apart. On 6 August the French fell back to Mercy's old position of the 3rd, and Enghien sent for 5,000 reinforcements.⁹

The withdrawal

When Enghien moved against Mercy's line of retreat, Mercy turned to meet him on 10 August near St. Peter, Schinzl writes, threw him back three times with his infantry and then drew off into the hills. His horses had not been unsaddled for eight days and had been fed on nothing but leaves. Britannica notes that he got away without great losses.¹⁰

Freiburg itself stayed in Bavarian hands, and Enghien turned north against Philippsburg. Britannica calls the battle one of the bloodiest and longest of the Thirty Years' War and counts 7,000 to 8,000 French losses against 2,500 Bavarian and imperial. Modern historians, it says, generally see it as a costly French tactical defeat, yet the French went on to master the middle Rhine.¹¹

Two great opponents

Enghien never forgot his opponent. When Mercy was killed at Alerheim the next summer, Schinzl records, the duke had a stone set up where he fell with the words "Sta viator, heroem calcas", stop, traveler, you tread on a hero, and said that in the two campaigns of 1644 and 1645 Mercy had not taken one step that did not bear the mark of the highest ability: he had foreseen the French plans as if he sat in their council of war.¹²