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.

[1] Sophia's descendants, of the House of Montbéliard, expanded Bar "by usurpation, conquest, purchase, and marriage" into a de facto autonomous state perched between France and Germany.

[1] In the Treaty of Bruges of 1301 Henry was forced to recognise all of his county west of the river Meuse as a fief of France.

The territory to the west of the Meuse was French since the Treaty of Verdun of 843, but in 1301 it became a direct fief of the crown, including its allodial parts.

[6] The ducal title was eventually accepted by the emperors, however, and the imperial tax register of 1532 records the "Duchy on the Meuse" (German: Herzogtum von der Maß) as a voting member of the Reichstag.

[7] In 1484 Peter II, Duke of Bourbon, regent for King Charles VIII of France, formally installed him in the Duchy of Bar.

[4] On 2 October 1735 the preliminary Treaty of Vienna between France and the Empire was drawn up, ending the War of the Polish Succession and granting Bar and Lorraine to the deposed king of Poland, Stanislaus Leszczynski.

In January 1736, Stanislaus formally renounced his claim to the Polish throne (although he was allowed to retain the royal title).

[9] On 30 September 1736, Stanislaus signed a convention, known as the Declaration of Meudon, whereby the French king would appoint the governor of Lorraine.

Stanislaus turned over the incomes from Bar and Lorraine to the French crown in exchange for a generous pension, which he used to fund construction projects in the duchies.