Russia has been a notoriously difficult country to invade, given its large size and generally large population throughout history. Freezing winters have also played a role in helping protect Russia, which was famously noted in 1812 during Napoleon's failed invasion of Russia. In response to European nations who saw the new French government as threat to the balance of powers, Napoleon annexed various parts of Europe and launched an invasion of Russia with over 600,000 soldiers. Napoleon invaded in the summer of 1812, but long fighting and a scorched earth policy by Russian forces prolonged the fighting and when a harsh winter arrived, the French army that lacked in supplies was reduced to under 100,000 soldiers. Eventually, Napoleon conceded his defeat, and left Russia in December, 1812.