Why did Napoleon III try to purchase Luxembourg from William III?

In 1867, Napoleon III sought to purchase the Grand Duchy of Luxembourg from William III, the King of the Netherlands, as part of his broader efforts to restore the prestige of the French Empire and check the growing influence of Prussia.12

At the time, Luxembourg’s status was complex: while it was a personal possession of the Dutch king, it had been a member of the German Confederation, and a Prussian military garrison remained stationed in its capital city. Napoleon III’s proposal triggered an immediate outcry in Germany and protests from other European powers, who viewed the potential acquisition as a threat to the balance of power.314

Ultimately, the crisis was resolved at a conference in London, where it was decided that Luxembourg would become an independent, neutral state with its fortifications dismantled, forcing Napoleon III to abandon his plans.12