The County of Metz originated from the frankish Metzgau. In the second half of the 9th century it went to the Gerhardiner (de), which held at the same time the County of Paris.
Over the Gerhardiner went the County—perhaps even in male lineage—to the Matfriede, which furthermore in 1047 received the title of Duke in Lorraine, namely Gerard IV, Duke of Alsace (c. 1030 – 1070), Seigneur of Châtenois (see also House of Châtenois).
The County of Metz was eventually merged into the Bishopric of Metz.
From 1189 the city of Metz was a Free Imperial City of the German Holy Roman Empire.