Why were many russians unhappy with tsar nicholas ii?

Tsar Nicholas was the Soviet Union's leader when they entered World War I. During that time, Russia was barely progressing economically, socially, and industrially and entering a war is definitely not what they needed. The people was mad at him because instead of developing their own country, they send everything to help the country win the war. 

The senetors had full control aka rich nobles but plebians part of the middle class would rise and revolt and gain equal citizenship