French author St.Hilaire wrote about Napoleonic lances: "The Polish lancer, as well as the French lancer distinguished himself by his elegant appearance; but the looks of this last were softer and the colors of his origin moderated, in respect to the military roughness of the first figure. As brave as the Polish lancer, the French lancer had a lively mood; he was more sober especially in his way of living, while the intemperance of Polish had become proverbial in the army."
The Poles were acknowledged to be the finest lancers in Europe and Russia, Prussia and Austria recruited their uhlan units from among the Polish subjects. It was followed by an imitative creation of lancer regiments all across Western Europe (France, Germany and and even the British got around to it after Napoleonic wars).
Before the Russian campaign Napoleon wanted to oppose the Cossacks who were nimble, tough warriors. The 1er, 3e, 8e, 9e, 10e and the 29e Régiment des Dragons were converted to 1er, 2e, 3e, 4e, 5e, and 6e Chevau-Légers Lanciers. The Vistula Uhlans and the Polish Guard lancers sent their troopers as instructors to the newly formed French units. Once trained by the Poles the regiments received tough lot of French officers "such as Perquit... who didn't recognize any danger." (Elting - "Swords Around a Throne") The 7e and 8e Chevau-Légers Lanciers were formed from Poles, by conversion of the 1st and 2nd Vistula Uhlans. They wore their traditional Polish style uniforms (no helmets). The 9th Regiment was made of Germans. It was formed by conversion of the 30e Chasseurs.