Final answer:
Alexander I did not enact the Great Reforms after Napoleon's defeat; it was Alexander II who emancipated the serfs in 1861 and introduced several governmental and societal reforms. These reforms were not enough for radicals, and Alexander II was assassinated in 1881.
Step-by-step explanation:
Reforms Enacted by Tsar Alexander I after Napoleon's Defeat
After the defeat of Napoleon, Tsar Alexander I did not implement reforms comparable to the Great Reforms of his nephew, Alexander II. The question seems to confuse Alexander I with Alexander II, who was the ruler responsible for enacting significant reforms including the emancipation of the serfs in 1861. This emancipation marked a turning point in Russian history, although it did not immediately transform the social or economic landscape of Russia due to the debt incurred by serfs to buy their freedom.
Alexander II also established local government systems known as Zemstvos, reduced censorship, introduced trial by jury, decreased military service terms, and limited harsh military discipline. He encouraged industrial development but faced a very rigid social structure that was resistant to change, particularly from the landowning nobility. His reforms were seen as insufficient by radicals, leading to his assassination in 1881 by a terrorist group.