The Vistula Legion, withdrawn from Spain in early 1812 and reorganized into a division (with a planned strength of 10,500 that was never fully attained) was part of Napoleon's invasion forces. Poles formed the largest foreign contingent, 98,000-strong (the entire French Grande Armée was about 600,000 strong). Polish Lancers of the Vistula Legion were the first unit to cross the Neman River when the Grand Armee entered Russia and, as part of the Imperial Guard, the first unit to enter Moscow. They distinguished themselves in the Battle of Borodino and, under Prince Józef Poniatowski (who personally saved Napoleon's life), were one of the units that served as the rear guard during Napoleon's retreat. This later led to the claim that just as they had been the first to enter it, they were the last to leave Russia. They sustained heavy losses during the campaign: only 26,000 of the original 98,000-strong contingent returned. The elite Vistula Legion entering Russia was about 7,000 strong; its strength at the end of the campaign was just 1,500. The definitive end of the Polish Legions came with the conclusion of Napoleon's career and the abolition of the Duchy of Warsaw. The Duchy was occupied by Prussian and Russian troops following Napoleon's retreat from Russia. The Polish troops remained loyal to him until the bitter end, with Polish units holding their ground at his last battles at Leipzig (15–19 October 1813) and Hanau (30–31 October 1813), where they sustained major losses. The Legion was recreated at Sedan in early 1814, and fought at Soissons, Reims, Arcis-sur-Aube and St-Dizier. After Napoleon's defeat in the War of the Sixth Coalition, when Napoleon was forced into exile on Elba, the only unit he was allowed to keep as guards were the Polish Lancers. While many Poles returned to the Polish territories, a unit of about 325 men under Colonel Golaszewski fought in Napoleon's final 1815 campaign, the "Hundred Days", participating in the Battle of Waterloo. After Napoleon's second and final defeat, some are said to have accompanied him to his exile on Saint Helena. In analyzing the creation of the Polish Legions, many historians have argued that Napoleon used the Poles as a source of recruits and had little desire to invest in the re-creation of the Polish state. Among the most notable of Napoleon's contemporary Polish detractors was Kościuszko, who refused to join the Legions, arguing that Napoleon would not restore Poland in any durable form.