How did Russia move from a Czarist to a communist regime?

Then, what event led to the communist control of Russia?

Bolshevik Revolution On November 6 and 7, 1917 (or October 24 and 25 ontheJulian calendar, which is why the event is often referredtoas the October Revolution), leftist revolutionaries ledbyBolshevik Party leader Vladimir Lenin launched a nearlybloodlesscoup d'état against the Duma'sprovisionalgovernment.

Similarly, why did countries fighting the war seek new allies? Why did both the Allied Powers andtheCentral Powers seek to gain new allies? Iftheyhad more allies, they would have more soldierstofight for them so the war would get over sooner.anagreement made by opposing sides in a war tostopfighting for a certain time; a truce.

Furthermore, why did Austria Hungary object to Serbia's desire?

The reason why Austria-HungaryopposedSerbia's desire to establish an independent stateisthat the rising nationalism in Serbia wasthreatening to theAustro-Hungarian empire. Moreover,the empire thoughtthat the nationalism could spread to other Slaviccountries, andwork as a unifying force against theempire.

Why did Great Britain became involved in the war?

Great Britain entered World War I on4August 1914 when the king declared war after theexpirationof an ultimatum to Germany. The official explanationfocused onprotecting Belgian neutrality, and The main reason,however, was toprevent a French defeat that would have left Germanyin control ofWestern Europe.