This placed the French army between Blücher's vanguard and his main body. Napoleon turned his attention to the vanguard and defeated Osten-Sacken and Yorck at Montmirail on 11 February; There were 9,000 Coalition casualties, to 1,100 French casualties. Napoleon attacked and defeated them again the next day at the Battle of Château-Thierry. There were 1,250 Prussian, 1,500 Russian casualties and nine cannons lost, to approximately 600 French casualties.