Count Johann Ludwig attempted to usurp the authority of the Bishopric of Metz in the county by dissolving the Benedictine Abbey in 1554.

He allowed Protestant refugees fleeing religious persecution in the Kingdom of France and the Duchy of Lorraine.

He approved the settlement of what became known as 'Seven Gallic Villages': Altwiller, Burbach, Diedendorf, Eywiller, Gœrlingen, Kirrberg, and Rauwiller.

Several large treaties were closed, in which the exact rights and boundaries of the Nassau and Palatinate territories were defined.

Catholic priests were converted to the new faith or removed from office; church property was confiscated; schools were established and patronage was acquired.

In 1629, Emperor Ferdinand II issued the Edict of Restitution, by which church property that had been confiscated after 1552 under the Peace of Passau, was returned to its previous owner.

Based on this Edict, the Prince Bishops of Mainz and Trier claimed substantial parts of the possessions of the Nassau.

Count Wilhelm Ludwig appealed and took the case to the Imperial Council of Princes Because he had refused to join the Catholic League, or to provide troops, the Emperor ignored him.

In 1635, Count Wilhelm Ludwig went to Frankfurt to attend a meeting of the Protestant states and their allies.

However, on 30 May 1635 a number of imperial estates, including the Electorates of Brandenburg and Saxony, had concluded the Peace of Prague and the Nassau Counts were expressly excluded from this agreement.

In November 1635 the imperial commissioner appeared in the Nassau lands and declared the Count had forfeited his counties and all their possessions; he was banned.

The Emperor gave the Duke of Lorraine the counties of Saarbrücken and Saarwerden and the bailiwick of Herbitzheim and the fortress of Homburg on the Blies as a reward for services rendered.

Count Gustav Adolph set about rebuilding the war-ravaged county, bringing back refugees, and recruiting settlers for agriculture and skilled workers.

He laid the basis for a proto-industrialized economy, which would later evolve into the highly industrialized Saarland region.

Despite the increase in revenues, his financial situation did not improve, due to the high spending on construction activities.

He largely continued his father's economic policies, but was increasingly subject to financial constraints.

Heinrich Ludwig died in 1797, leaving the county to his cousin Karl Wilhelm of Nassau-Usingen.