Some 160,000 French soldiers fought against Prussia (increasing in number as the campaign went on, with reinforcements arriving across the Wesel bridgehead from the peripheral theatre surrounding the recently formed Kingdom of Holland) advancing with such speed that Napoleon was able to destroy as an effective military force the entire quarter of a million-strong Prussian army. The Prussians sustained 65,000 casualties (including the deaths of two members of the royal family) lost a further 150,000 prisoners, over 4,000 artillery pieces, and over 100,000 muskets stockpiled in Berlin. The French suffered around 15,000 casualties for the whole campaign. Napoleon entered Berlin on 27 October 1806 and visited the tomb of Frederick the Great, telling his marshals to show their respect, saying, "If he were alive we wouldn't be here today".