Nicholas I was the Emperor of Russia from 1825 until his death in 1855. He was known for his conservative policies and strong autocratic rule. Nicholas I aimed to strengthen the Russian Empire and maintain its influence in Europe, often using military force to suppress dissent and uphold his authority. During his reign, Nicholas I faced several challenges, including the Decembrist Revolt in 1825, which was an uprising by army officers seeking reform. He also oversaw the Crimean War (1853-1856), a conflict that ultimately exposed weaknesses in the Russian military and administration, leading to significant reforms after his death.