Lotharingia was a kingdom in western Europe, named after Lothair, King of Lotharingia (reigned 855-869), who received it in 855 from his father, Lothair I (795-855), Holy Roman Emperor.
It comprised (broadly speaking) the present:
- Netherlands
- Belgium
- Luxembourg
- North Rhine-Westphalia, Rhineland-Palatinate, Saarland (Germany)
- Lorraine, Alsace (France)