10 of the Deadliest Battles of the 20th Century

The 20th century was marked by dramatic upheaval and conflict, resulting in countless battles that would go down in history as some of the deadliest ever fought. While the two World Wars are often seen as the primary theaters of destruction during this time, numerous other wars claimed the lives of millions, with devastating impacts on soldiers and civilians alike. From the jungles of Southeast Asia to the deserts of Africa, the bloodshed was immense. Here, we explore ten of the deadliest non-World War battles of the century—conflicts that profoundly influenced the political landscapes of their respective regions and left lasting scars on humanity.

1. The Nigerian Civil War (1967-1970)

Often referred to as the Biafran War, the Nigerian Civil War resulted in an estimated one million deaths, primarily from starvation. The conflict arose from ethnic tensions and economic disparities within Nigeria, pitting the southeastern region of Biafra against the Nigerian government. The war drew international attention, particularly due to the humanitarian crisis that ensued.

2. The Chinese Civil War (1927-1949)

Spanning over two decades, the Chinese Civil War led to an estimated 8 million fatalities. The conflict was fought between the Nationalists (Kuomintang) and the Communists (CPC) and culminated in the establishment of the People’s Republic of China in 1949. The war involved a series of violent battles, mass executions, and widespread suffering, contributing to significant societal changes in China.

3. The Vietnam War (1955-1975)

While this conflict is often linked with American engagement, the Vietnam War was primarily a civil war that saw devastating casualties. Estimates suggest that around 2 million Vietnamese civilians and over 1 million combatants were killed during the conflict. The war also left a lasting impact on Southeast Asia and was notable for its chilling tactics, including the widespread use of chemical warfare.

4. The Korean War (1950-1953)

Often dubbed “The Forgotten War,” the Korean War resulted in approximately 3 million deaths. The battle lines were drawn between North and South Korea, leading to a brutal stand-off that involved international forces, including those from the United States and China. The war’s legacy continues to influence geopolitics in the Korean Peninsula to this day.

5. The Bangladesh Liberation War (1971)

The liberation struggle in Bangladesh, then East Pakistan, resulted in the deaths of an estimated 300,000 to 3 million people, although exact numbers are debated. The conflict was marked by severe human rights violations, including genocide and the large-scale displacement of people. The struggle for independence ultimately led to the creation of Bangladesh and has been pivotal in shaping South Asian politics.

6. The Iran-Iraq War (1980-1988)

Spanning nearly a decade, the Iran-Iraq War is estimated to have claimed about 1 million lives, with both military and civilian casualties. The war’s causes include territorial disputes and religious sectarianism, and it resulted in massive destruction and economic turmoil for both nations. It remains one of the longest and deadliest conventional wars in modern history.

7. The Algerian War of Independence (1954-1962)

This brutal conflict saw around 1.5 million Algerians lose their lives in the fight against French colonial rule. The war was characterized by guerrilla warfare and extreme violence, including torture and summary executions. The eventual victory of the National Liberation Front (FLN) marked a significant moment in the decolonization process in Africa.

8. The Russo-Japanese War (1904-1905)

A conflict with significant international implications, the Russo-Japanese War marked the first major military victory of an Asian power over a European one in modern history. An estimated 130,000 to 200,000 people died due to the warfare, disease, and famine that crippled both nations. It redefined the balance of power in East Asia and influenced the course of global geopolitics.

9. The Mexican Revolution (1910-1920)

The Mexican Revolution led to significant political and social changes in Mexico but also resulted in estimated deaths of over 1 million, attributed to battles, disease, and famine. The struggle was characterized by various factions fighting for land reform and social justice, leaving a profound impact on Mexican society.

10. The Ethiopian Civil War (1974-1991)

This conflict led to the rise and fall of the Derg regime and resulted in approximately 1 million deaths. The war involved multiple factions, including ethnic guerrilla movements and the government, and it was closely intertwined with famine, displacement, and oppression. The legacy of the war continues to influence Ethiopia’s political landscape.