Reasons for Rev. of March 1917:

Defeat of Russia following entry in WWI
Some argue that Rev. was inevitable regardless of WWI (terrible living standards)
Incompetence of the Czar
Corrupt and inefficient Gov.
Weak ruler (Nicholas II)
Rasputin damage the reputation of the royal family in the eyes of other nobles (he was seen to be the de facto ruler of the country)
Food shortages
Army losses in 1916 (the army morale declined)
The Czar assumed command of the army and was associated with military defeat
Formation of the Provisional Gov.
Established by the Duma
A soviet committee was established
Causes of the October (Bolshevik) Rev.
Weaknesses/mistakes of Prov. Gov. : failed to decisively — didn’t satisfy demands for change / the power of the Soviets / allowed opposition to form / kept Russia in the war / handicapped by internal divisions (not efficient and united)
The power of the Bolsheviks
The return of Lenin
The Mensheviks supported the Prov. Gov. and opposition sided with the Bolsheviks as a result
Lenin adapted Marxist doctrine to fit revolutionary needs
The simple message of Bolshevism: "Peace, bread and land"
The Bolsheviks strengthened power in the cities as opposed to the countryside which meant success in elections.
They gained a military force (the Red Guards) which other political parties did not have
Benefited from divisions amongst their opponents
The Bolshevik Revolution

Timing was a result of Lenin’s belief that war with Germany must be ended at any costs.
Were the 1917 Revolutions inevitable?
Improvement in living standards meant chances of revolution might fade: the establishment of a middle peasant class / improvements in working conditions / lack of incentive in revolutionary parties
BUT The Czar had failed to carry out his promised reforms (the situation was deteriorating before WWI)

Growing agitation amongst the workers / combined with the fact that the army was not loyal to the Czar following Russian defeat in war.