It reinstated Emperor Louis the Pious and reversed his former conviction on crimes — none of which he actually committed — and deposed the Archbishop of Rheims, Ebbo.

On 28 February 835, in Mainz, Ebbo admitted that Louis had not committed the crimes of which he had been indicted and for which he had been deposed as Holy Roman Emperor.

In 1792, Thionville was besieged by the Duke of Brunswick, who unsuccessfully sought to defeat the French Revolution and restore Louis XVI to the royal throne.

The writer François-René de Chateaubriand was left for dead during Condé's military émigré expedition against Thionville in 1792.

After the Franco-Prussian War of 1870, the area of Alsace-Lorraine was annexed by the newly created German Empire in 1871 by the Treaty of Frankfurt and became a Reichsland.

Following the armistice with Germany ending the First World War, the French army entered Diedenhofen in November 1918 and the city was transferred to France by the Treaty of Versailles in 1919, after it again became Thionville.

After experiencing, along with all of France, an economic upswing during the postwar decades (trente glorieuses), the heavy industry of Thionville suffered setbacks beginning in the 1970s.

Jean-Marie Demange, who had served as the town's mayor for thirteen years, committed suicide in 2008 after killing his mistress with two gunshots in the head.

The Gare de Thionville railway station offers connections with Luxembourg, Metz, Nancy, Paris, Strasbourg, Brussels, Zürich, and several regional destinations.

[4] The population of Thionville increased mainly in the first half of the 20th century due to industrial development of the Upper Moselle basin.