At different times, he was General Field Marshal of the Holy Roman Empire of German Nation and of the United Provinces of the Netherlands under Prince William III of Orange.

For these feats, King John III Sobieski of Poland granted him the Order of the White Eagle, the highest Polish distinction.

During the War of the Spanish Succession, he was tasked with implementing the imperial ban against Elector Joseph Clemens of Cologne, who had sided with France against the Empire.

Prince William Louis left three sons, who divided the Nassau territories on 31 March 1659 divided area: John Louis received Ottweiler, Gustav Adolph kept Saarbrücken and Walrad received Usingen and became the founder of a new branch.

The town gained significantly in prestige and importance by being the seat of a Nassau and also benefited from Walrad's urban construction zeal.

In 1905, the grateful city council erected a monument for Walrad in the palace gardens (now a public park).