Treaty of Meerssen
The Bishopric of Metz was a prince-bishopric of the Holy Roman Empire. It was one of the Three Bishoprics that were annexed by France in 1552. The Bishops of Metz had already ruled over a significant amount of territories within the former Kingdom of Lotharingia, which by the 870 Treaty of Meerssen became a part of East Francia. They had to struggle for their independence from the Dukes of Lorraine, acquired the lands of the Counts of Metz, but had to face the rise of their capital Metz to the status of an Imperial City in 1189. In 1234 the unrest of the Metz citizens forced the bishops to move their residence to Vic-sur-Seille.