Emperor Alexander I was the Tsar of Russia from 1801 to 1825. He was born on December 23, 1777, and became known for his role in the Napoleonic Wars. Alexander initially allied with Napoleon Bonaparte but later turned against him, leading a coalition of European powers to defeat Napoleon in 1814. Alexander I is also remembered for his reforms in Russia, including efforts to modernize the government and promote education. He was a key figure at the Congress of Vienna in 1815, which aimed to restore stability in Europe after the turmoil of the Napoleonic Wars. He died on December 1, 1825.