Their remains were buried at Soissons, but were afterwards removed, partly by Charlemagne to Osnabruck (where a festival is observed annually on the 10th of June) and partly to the chapel of St Lawrence in Rome.
The court of Vienna had treated the Silesian Protestants with tyrannical severity, in direct contravention of the treaty of Osnabruck, of which Sweden was one of the guarantors; and Charles demanded summary and complete restitution so dictatorially that the emperor prepared for war.
He was educated at the Carolinum, an endowed school at Osnabruck, and studied at the universities of Gottingen and Heidelberg.
In 1836 he settled down as an advocate in Osnabruck: his abilities soon procured him a considerable practice, and he was appointed president of the Catholic Consistorium.
Windthorst's Ausgewahlte Reden were published in three volumes (Osnabruck, 1901-1902).