Jean Louis d'Erlach

Johann Ludwig von Erlach (30 October 1595 – 26 January 1650) was a Swiss mercenary and military commander of the Thirty Years' War.

Biography Erlach was born on 30 October 1595 in Bern, canton of Bern, into the Bernese patrician Erlach family. He was the son of Colonel Rudolf von Erlach, Landvogt of Morges, and Katharina von Mülinen.

As the Duke of Saxe-Weimar's chief of staff, Erlach organized the Rhine campaign of 1638 that led to the conquest of Laufenburg, Rheinfelden and the fortified Habsburg stronghold of Breisach. Back in French service, he was appointed governor of Breisach and promoted to lieutenant-general in 1647. Erlach fought in the Flanders campaign of 1648 at the end of the war, and became the commander of the French army in the Holy Roman Empire in 1649. During the Congress of Westphalia he supported the French ambassadors in the negotiations regarding Alsace, and pushed for the annexation of the four ("forest cities") of Rheinfelden, Säckingen, Laufenburg and Waldshut. Erlach died in Breisach on 26 January 1650, aged 55, and was buried in Schinznach-Dorf.