René II was Count of Vaudémont from 1470, Duke of Lorraine from 1473, and Duke of Bar from 1483 to 1508. He claimed the crown of the Kingdom of Naples and the County of Provence as the Duke of Calabria 1480–1493 and as King of Naples and Jerusalem 1493–1508. He succeeded his uncle John of Vaudémont as Count of Harcourt in 1473, exchanging it for the county of Aumale in 1495. He succeeded as Count of Guise in 1504.

The County of Bar, later Duchy of Bar, was a principality of the Holy Roman Empire encompassing the pays de Barrois and centred on the city of Bar-le-Duc. It was held by the House of Montbéliard from the 11th century. Part of the county, the so-called Barrois mouvant, became a fief of the Kingdom of France in 1301 and was elevated to a duchy in 1354. The Barrois non-mouvant remained a part of the Empire. From 1480, it was united to the imperial Duchy of Lorraine.