1917 was PROOF that it DID happen! The 2 revolutions of 1917 (along with other events preceding it) brought down a 200+ year tzarist autocratic regime (Romanov Dynasty).

There are many other such events in history. For more information, check out "Revolutionary Movements in World History: From 1750 to the Present (3 vol. set)" [goodreads.com/book/show…]

Another good book to check out is: "Revolutions and Revolutionary Movements" by James Defronzo [goodreads.com/book/show…]