War. Death. Destruction. A tale as old as time. A cycle that never ends. The millions of lives lost to mankind’s love of warfare is startling in quantity and impossible to grasp. 

Some wars are so ancient, the world seems to have forgotten they ever occurred. Some are so recent, it is like they happened only yesterday. But both have staggering cultural, political, economic and social repercussions. Here is a look through history at some of the most costly wars mankind has endured. 


22. The Biafran War

The Biafran War, also known as the Nigerian Civil War, was fought between the government of Nigeria and the secessionist state of Biafra from July 6, 1967, to January 15, 1970. After Britain formally decolonized from Nigeria in the early 1960s, political, economic, ethnic, cultural and religious tensions grew and Biafra sought succession. An estimated 2 million civilians perished due to famine during the blockade.


21. The Japanese Invasions of Korea

The two Japanese invasions of Korea between 1592 and 1598 CE are also known as the “Imjin Wars.” The first invasion started when Toyotomi Hideyoshi, a Japanese military leader, put into motion his long-held plan to invade China through Korea. It got off to a successful start as cities like Pyongyang and Seoul were captured, but eventually, the combined operations of the Korean navy, a large land army from Ming China and well-organized local rebels resulted in the first invasion stalling in 1593 CE. After unsuccessful peace talks, Hideyoshi launched a second, much less successful invasion in 1597 CE, and when the warlord died the next year, the Japanese forces withdrew. The conflict led to a death toll of 1 million for Korea.

20. The Iran–Iraq War

This prolonged military conflict between Iran and Iraq lasted through most of the 1980s. Open warfare began on September 22, 1980, when Iraqi armed forces invaded western Iran along the countries’ joint border. The roots of the war lay in a number of territorial and political disputes between Iraq and Iran. Fighting was ended by a 1988 cease-fire, though the withdrawal of troops did not take place until the signing of a formal peace agreement on August 16, 1990. Estimates of total casualties range from 1,000,000 to twice that number, with Iran likely suffering the greatest losses. Both sides fought brutally with the use of chemical weapons and deliberate attacks on civilian targets.

19. The Siege of Jerusalem

The Siege of Jerusalem of 70 CE marks the Roman military blockading Jerusalem during the First Jewish Revolt. The Romans encircled the city with a wall to cut off supplies to the city completely and thereby drive the Jews to starvation. They also destroyed much of the city, including the “Second Temple,” a center of worship and national identity in ancient Israel. The fall of the city marked the conclusion of a four-year campaign against the Jewish insurgency in Judaea. The majority of information on the siege comes from the notes of the Jewish historian Flavius Josephus. According to these notes, 1.1 million civilians died during the siege, mainly as a result of violence and famine.

18. The Korean War

At the end of the Second World War, Korea was divided along an internal border between North and South Korea (sometimes referred to as “the 38th Parallel”). Tensions reached an explosive high in June 1950 when North Korea—supplied and advised by the Soviet Union—invaded the South. The United Nations—with the United States as the principal participant—joined the war on the side of the South Koreans, and the People’s Republic of China came to North Korea’s aid. After more than a million combat casualties had been suffered on both sides, the fighting ended in July 1953 with Korea still divided into two hostile states—North and South, as it remains today.

17. The Mexican Revolution

The Mexican Revolution, which began in 1910, was the first major social revolution of the 20th century. It was the dawn of many changes in Mexico’s government, including the end of dictatorship in Mexico and the establishment of a constitutional republic. Though a constitution drafted in 1917 formalized many of the reforms sought by rebel groups, periodic violence continued into the 1930s. It has been difficult for historians to quantify the death toll of this period of Mexican history, but most estimates range from 1 to 2 million.

16. Shaka´s Conquest

Shaka´s Conquest is a term used for a series of massive and violent conquests in Southern Africa led by Skaha, one of history’s most influential monarchs of the Zulu Kingdom. In the first half of the 19th century, Shaka led a large army that invaded a number of regions in Southern Africa, destroying tribe after tribe in a deadly cycle of warfare and conquest. It is estimated that up to 2 million tribal people fell victim. Shaka himself was killed by three assassins in 1828.

15. The Goguryeo–Sui War

The Goguryeo-Sui Wars refer to a series of campaigns launched by the Sui Dynasty of China against the Goguryeo kingdom of Korea between 598 C.E. and 614 C.E. The Sui believed that Goguryeo geographically belonged to China. This was their motivation to launch four mighty invasions, all of which failed. Goguryeo defeated the Sui Dynasty, leading to the collapse of the empire, but Goguryeo refrained from invading China to assume control of China. This was Goguryeo’s downfall—they later fell to a combined Silla-Tang Dynasty attack in 668 C.E. The Goguryeo–Sui War brought a death toll of 2 million people, but this number does not include Korean and civilian casualties.

14. French Wars of Religion

The time frame of these wars was 1562 to 1598 and these years represent the conflict in France between Protestants (Huguenots) and Roman Catholics. The exact number of wars and their dates are still debated by historians but it is estimated that up to 4 million people died as a result of the war, famine and war-related diseases.

13. The Second Congo War

The Second Congo War is the deadliest war in modern African history claiming the lives of up to 5.4 million deaths, mostly through disease and starvation. In the First Congo War, the support of Rwanda and Uganda enabled Congolese rebel, Laurent Désiré-Kabila, to overthrow Mobutu Sese Seko's government. However, after Kabila was installed as the new President, he broke ties with Rwanda and Uganda. The Second Congo War kicked off when they retaliated by invading the Democratic Republic of the Congo. Within a few months, no less than nine African countries were involved in the conflict in the Congo, and by its end, nearly 20 rebel army groups were fighting in what had become one of the deadliest conflicts in recent history.

12. The Napoleonic Wars

Napoleonic Wars, a series of wars (fought between 1803 and 1815) between Napoleonic France and shifting alliances of other European powers that produced a brief French dominance over most of Europe. The death toll of these conflicts is estimated to be around 5 million. Along with the French Revolutionary Wars, the Napoleonic Wars constitute a 23-year period of recurrent conflict that concluded only with the Battle of Waterloo and Napoleon’s second renunciation of the throne on June 22, 1815. Napoleon was an incredibly successful military leader. He fought about 60 battles during his career and lost just seven, mostly at the end of his reign.

11. The Thirty Years´ War

Fought between 1618 and 1648, the Thirty Years War was caused by a religious divide between German Catholics and Protestants in the Holy Roman Empire and spread to spark a strong religious divide throughout most of Europe. In the end, the conflict changed the geopolitical face of Europe and the role of religion and nation-states in society. The death toll estimates differ significantly but the most probable count suggests that about 8 million people, including civilians, died in this very lengthy war.