Explanation:

Junkers were Russian army cadets assigned to defend government buildings. 

The Junker mutiny was a counterrevolutionary mutiny of military school cadets in Petrograd against the Bolsheviks in October 1917.

On October 29 of 1917, students of junker schools in Petrograd rose up against the Bolsheviks under the leadership of the Committee for Salvation of Motherland and Revolution, organised by the Right Esers. The goal of the mutiny was to support the Kerensky-Krasnov uprising (October 26–31, 1917). The rebellious students wanted to seize the city telephone exchange, Peter and Paul Fortress, Smolny and arrest the Soviet government together with the Bolshevik leaders.