The famous Russian ruler known as the "Great Reformer" was Tsar Alexander II, who reigned from 1855 to 1881. He is best known for initiating a series of significant reforms aimed at modernizing Russia, particularly through the emancipation of the serfs in 1861, which sought to improve social and economic conditions. Alexander II also implemented judicial reforms, expanded education, and introduced local self-governance through the establishment of the zemstvo system. His policies aimed to transform Russia into a more progressive state, though they faced substantial resistance, and his assassination in 1881 ended many of these reform efforts.