#10
Russian civil war
The Russia civil war was fought from 1918 - 1921. It caused a total of 5,000,000 - 9,000,000 deaths. The war started as a result of many groups that had formed against Lenin's Bolsheviks. This resulted in the Bolsheviks wanting to wipe out all their enemies. The war resulted in a Bolshevik victory over the whites.
#9
Mughal-Maratha wars
Also referred to as the Deccan war was a 27 year long war fought between the Maratha Empire and the Mughal Empire from 1680-1707. The war costed more than 5,000,000 lives and many more due to the damages done by the war. It started when Mughal emperor Aurangzeb invaded Maratha. The war resulted in a defeat for the Mughals and was a great example of guerrilla warfare.
#8
Chinese civil war
The Chinese civil war was fought from 1927 - 1949 because of the difference in opinions of Chinese communist party and the Chinese nationalist party. The war claimed a total of 8,000,000 - 11,000,000 lives but a lot more died because of disease and starvation. The war was won by the communists, gaining control of mainland China and establishing the People's republic of China.
#7
Dungan revolt
Also known as the Tongzhi Hui Revolt, Dungan revilt was a war fought between many ethnic groups in china from 1895-1896. The dungan revolt caused a total of 8,000,000 - 20,000,000 lives. It started over a simple dispute about the bamboo pole prices and elevated it as a ethnic revolt. It result in the victory for Qing Dynasty.
#6
Spain vs Inca empire
The Spanish conquest of the Inca empire also known as the conquest of Peru was a war fought between 1532 - 1572. The war caused more than 8,400,000 deaths and marked the end of 300 years of Inca civilization.
#5
World war 1
World war 1 was fought between 1914 - 1918 and caused 16,000,000 - 40,000,000 deaths worldwide. It was started due to the assassination of Archduke Franz Ferdinand of Austria, his murder kicked off a war across Europe that spread to the rest of the world. The war resulted as a victory for the Allies, but set a corner stone for world war 2.
#4
Second sino-japanese war
The second sino-japanese war was fought between China and Japan from 1937 - 1945. It is the biggest asian war of the 20th century and is also called the Asian holocaust. The war caused a total of 20,000,000 - 25,000,000 deaths and was a part of world war 2. It started as a primary military conflict between republic of China and the emperor of Japan. The Japanese surrendered on 2nd September 1945.
#3
Taiping rebellion
The Taiping rebellion also known as the Taiping revolution was a war fought between the Qing Dynasty and tha Han Dynasty. The war was fought from 1850 - 1864 and costed a total of 20,000,000 to 70,000,000 deaths. It started as a revolt against the Qing Dynasty as 90% of the population was Han and they were not happy with the minority rule.
#2
Ming to Qing
The transition from Ming to Qing occured from 1618 - 1683 and was the transition between two major dynasties in Chinese history. The war costed more than 25,000,000 lives and ended with the fall of Ming Dynasty.
#1
World war 2
Known as the deadliest war I'm human history, world war 2 was fought from 1939 - 1945 and affected the entire world. It caused a total of 85,000,000 deaths with the Allies declaring victory. It saw the destruction of many historical and important places like the Pearl Harbor, and saw the single most man made destruction in the form of Hiroshima-nagasaki bombing. The war started from Hitler's invasion of Poland, and ended with the Axis power's surrender.