For the 1905 Revolution, it was the Russo-Japanese War. That revolution was a failure, but Russia basically had to crush the revolution at the cost of their war with Japan. The mutiny of the Potemkin happened less than two months after the Battle of Tsushima where the Russian navy lost all their battleships. In general, if you plot the major events of the 1905 Revolution like Bloody Sunday and major battles of the Russo-Japanese War like the Battle of Mukden, they basically completely clutter 1905. It's not a coincidence that the Treaty of Portsmouth was signed less than two months before the October Manifesto.
For the February Revolution, it's WWI in general. War meant the populace was forced to offer up their sons, brothers, and fathers to the meat grinder on top of domestic life just deteriorating in general. Widespread conscription also meant that you have a huge swath of angry people with arms.
For the October Revolution, it was due to the provisional government wanting to continue participating in WWI. There was also that infamous event in history where Lenin was able to sneak back into Russia from Switzerland courtesy of the German Kaiser and his agents. Obviously, he was no socialist. He mostly saw Lenin as someone who would greatly destabilize Russia, his imperialist rival. The October Revolution would've never happened if Lenin was still stuck in Switzerland, and the only reason why he was able to get back to Russia was because Russia's imperialist rival thought it would be a good idea.
For all three cases, you had external forces that overwhelmed the old regime and opened windows of opportunity for revolutionaries to exploit.
For the 1905 Revolution, it was the Russo-Japanese War. That revolution was a failure, but Russia basically had to crush the revolution at the cost of their war with Japan. The mutiny of the Potemkin happened less than two months after the Battle of Tsushima where the Russian navy lost all their battleships. In general, if you plot the major events of the 1905 Revolution like Bloody Sunday and major battles of the Russo-Japanese War like the Battle of Mukden, they basically completely clutter 1905. It's not a coincidence that the Treaty of Portsmouth was signed less than two months before the October Manifesto.
For the February Revolution, it's WWI in general. War meant the populace was forced to offer up their sons, brothers, and fathers to the meat grinder on top of domestic life just deteriorating in general. Widespread conscription also meant that you have a huge swath of angry people with arms.
For the October Revolution, it was due to the provisional government wanting to continue participating in WWI. There was also that infamous event in history where Lenin was able to sneak back into Russia from Switzerland courtesy of the German Kaiser and his agents. Obviously, he was no socialist. He mostly saw Lenin as someone who would greatly destabilize Russia, his imperialist rival. The October Revolution would've never happened if Lenin was still stuck in Switzerland, and the only reason why he was able to get back to Russia was because Russia's imperialist rival thought it would be a good idea.
For all three cases, you had external forces that overwhelmed the old regime and opened windows of opportunity for revolutionaries to exploit.