The new formation of uhlans proved to be not only fast and effective, but also very influential: during the Napoleonic Wars the uhlans of the Duchy of Warsaw were among the most effective cavalry units and by the end of that period most of European states copied both their tactics and their uniforms. Together with the French, the Polish cavalry took part in many of the most notable battles of the Napoleonic period, including the battles of Smolensk, Fuengirola, Raszyn, and many others. Also, the Polish cavalrymen were the first unit of the Napoleon's Grande Armée to enter Moscow Kremlin during the Napoleon's invasion of Russia. Finally, the Polish cavalry detachments were also present in Haiti, where they helped the French administration to quell a slave revolt. However, perhaps the most notable success of the Polish cavalry in that period (and certainly the best known) is the Battle of Somosierra, a part of the Peninsular War.