The October revolution has been the subject of numerous books and there is only room here for the briefest of introductions.
Russia endured two revolutions in 1917. The first sprung from a wave of strikes and spontaneous revolts in rear echelon units of the Army. The result effectively paralysed the nation and forced the abdication of the Czar and his replacement by a Provisional Government under the leadership of Alexander Kerensky (who’s father had been Lenin’s school headmaster). The revolution was largely the product of and capitalised on by the middle-classes and the intellectual elite of Russia
In September 1917 General Kornilov attempted a coup d’etat which generated fear that the Czar would return and impose even harsher government than before. Kerensky seemed unable to control matters.
The Bolshevik leader Vladimir Iliyitch Ulyanov had taken the revolutionary name of Lenin. He had been in exile from Russia and was secretly returned there with the aid of Germany who hoped he would ferment trouble in his homeland and disrupt the war effort. He was an avowed pacifist but that attitude would change with the realities of taking power in Russia.
The practical elements of the October revolution were the same as any rising or military coup. Key points in Petrograd were occupied, communication centres, railway stations and government offices. Members of the Provisional Government were arrested or forced to flee, leaving Lenin as head of a well organised and tightly focused group in a position to spread their message across the nation.
Russia was sliding inexorably towards the disaster of civil war.