This is done from memory - obvisiously it doesn't cover everything - I shall try to do the other leaders (inc the PG too) Hopefully this is helpful. NB: There's no spell correct so some errors may be present.
Alexander II - 'The liberator Tsar' - He had to balance liberal reforms with autocratic rule.
Abolition of Serfdom: 1861 - This followed the defeat in the Crimean war, it was seen Russia needed to moderinise from its backwards state. This additionally began the concept behind Stalion's Industrialisation, one of the principles of emanicpation was "the peasants going into the factories"
60% of peasants were worse off following Emanicipation. They now lived at the mercy of the landowners.
Alexander II did Military reforms 1974 - this created universal conscription of all social classes, i.e Nobles too not just serfs, making a much more efficent army.
Censorship was relaxed, this was a reform seen too under the Provisional Government and Khrushchev, and like the PG this led to an early death. The People's Will assassinated Alexander II in 1881. There was an attempt on his life in 1880, these led to slower pace of reforms, and more repressive measures.
Educational reforms leading to 1000 uncensored books and admissions of women into educational classes (this is very significant for its time)
Repressive measures include the trial of the 50 and trial of the 193 alongside the Polish uprising in 1883
The Russo-Turkish war was also won, which while demonstarting progression of militry reforms and modernisation, it amounted to little in actual fact.
An interesting point to understand is the opposition to leaders in their aims and actions can contradict and cause issues. For example, the People's Will assassinating Alexander II lead to the reaction era under Alexander III (Repression) The assassination attempt on lenin (1918) led to the Red Terror, The aims of the Bolsheviks and Mensheviks splitting themselves (ie when was the tiem for revolting? was it after the economy had healed?) and so on. This is interesting to note.
Alexander III - The Reaction era
Essentially this counter reformed the reforms of his father Alexander II, the aim was to restore traditional Russia values, everywhere would speak Russian apart from the courts who spoke French (it sounded posh)
"I'm always happy when they beat the Jews" The jews were sent to the pale (isolated from Russia). Internal passports were used and the cultrual restrictions enforced. Land Captains…