When the November Uprising, a struggle for Polish independence, broke out on November 29, 1830, against the Russian Empire, Bem immediately joined the Polish insurgents. He arrived in Warsaw, was given a major's commission and the command of the 4th Light Cavalry Battalion, which he led during the Battles of Iganie and Ostrołęka. During the Battle of Ostrołęka, Bem's forces bravely charged the Russian opponents. Although the Polish army suffered a serious defeat with a loss of 6,000 men, Bem's actions prevented the destruction of the entire army. For his valour on the battlefield, Bem was awarded the Virtuti Militari Golden Cross and promoted to the rank of Brigadier General. He was steadfastly against capitulation until the very end of the Uprising, during the desperate defence of Warsaw against Prince Paskievich (September 27, 1831). Nonetheless, the Polish army was eventually compelled to lay down arms on October 5, 1831, and crossed the Russian–Prussian partitional border under the command of General Maciej Rybiński in the Great Emigration.