What were the causes of the 1917 Russian Revolution?

1905 saw Bloody Sunday occur when Tsarist Russian Imperial forces massacred protestors angry with famine and feudalism. This resentment continued to fester until February 1917 when in amidst of famine, inflation, poor land distribution and autocratic rule as well as Russian losses in World War One, the Tsar abdicated the throne. The failure of coalitions during the Provisional Government interregnum between February and October gave the Bolshevik Party ample ground to seize power in a Russia with a history of autocratic leadership. Leftwing historians argue that Vladimir Lenin's charismatic leadership and public dissatisfaction with the ancient regime made October 1917 a popular revolution from below. On the other hand, recent research since the end of the Cold War in 1989 by American historian Richard Pipes argues that the revolution was in fact a coup, and the party did not enjoy popular support, evidenced by the fierce opposition in the following Russian Civil War.