What are the reasons for the February Revolution? Why did the monarchy in Russia collapse so quickly?

The reasons for the February Revolution are:

1) Food crisis in the state;

2) Economic crisis;

3) The poor position of the Russian troops at the front;

4) Decline of the authority of the king;

5) The failure of the government in solving pressing problems of the state.

So in 1917, the Romanovs were overthrown from the royal throne, and then they were executed. So the power of the Bolsheviks was established in the state, which changed the vector of the country’s development.