1. Russian Civil War (1917 – 1922)
   Battle of Gettysburg (American Civil War) (1863)
2. Iran–Iraq War (1980 – 1988)
   Atomic Bombings of Japan (World War II) (1945)

It took three days of fighting (July 1 – 3, 1863) in the Battle of Gettysburg before Union forces, led by General George Meade, could defeat a Confederate Army under the command of General Robert E. Lee. Approximately 100,000 men died in the battle which is often regarded as one of the American Civil War’s major turning points.

1. Pequot War (1634 – 1638)
   Spanish-American War (1898)
2. Battle of Marathon (Greco-Persian War) (490 BCE)
   Gulf War (1990 – 1991)

Also called the Persian Gulf War, this conflict began with Iraq’s invasion and annexation of Kuwait under orders from its president, Saddam Hussein. The action triggered an international response (codenamed Operations Desert Shield and Desert Storm, by the U.S.). The international coalition which aimed to repel the invasion and protect neighboring Saudi Arabia included troops from many of the world’s most powerful nations.

1. Siege of Orleans (Hundred Years’ War) (1429)
   Battle of Stalingrad (World War II) (1942)
2. Spanish conquest of the Aztec Empire (1519 – 1521)
   Battle of the Nile (French Revolutionary Wars) (1798)

The arrival of Joan of Arc is credited with turning the tide for the French city of Orleans, which had been under siege by the English for nearly six months. Joan, who was acting on her visions of God, proved to be an inspiration to the city’s citizens. She is also credited with taking part in the actual battle and suggesting tactical maneuvers.

1. American Civil War (1861 – 1865)
   War of a Thousand Days (1899 – 1903)
2. Second Congo War (1998 – 2003)
   Korean War (1950 – 1953)

North Korea began its invasion of South Korea on June 20, 1950 and the ensuing conflict lasted for 3 years, 1 month and 2 days. North Korea got assistance from both China and the Soviet Union while South Korea was assisted by United Nations forces led by the U.S. Both countries signed an armistice, agreeing to end fighting but did not agree to end the war until 2018.

1. World War II (1939 – 1945)
   Second Sino-Japanese War (1937 – 1945)
2. War of 1812 (1812 – 1815)
   Phony War (1939 – 1940)

The French Revolutionary and Napoleonic Wars (1792 – 1815) had England and France in almost constant battle with each other. During this time, England attempted to block America’s neutral trading with France and began the practice of impressment of American sailors on merchant ships – capturing them and forcing them to serve in the British military. As a result, America declared war on England, which lasted until both sides signed the Treaty of Ghent.

1. Battle of Hastings (Norman conquest of England) (1066)
   Seven Years' War (1756 – 1763)
2. Invasion of Normandy (World War II) (1944)
   Battle of the Bulge (World War II) (1944)

William the Conqueror, Duke of Normandy, had been promised the throne by then King of England, Edward the Confessor. Edward changed his mind on his deathbed and handed the throne to nobleman Harold Godwinson causing William to gather his troops to challenge Harold. After Harold’s death on October 14, 1066 in the Battle of Hastings, William journeyed on to London where he was proclaimed King of England on Christmas Day, 1066.

1. Battle of Waterloo (Napoleonic Wars) (1815)
   World War I (1914 – 1918)
2. Vietnam War (1955 – 1975)
   American Revolutionary War (1775 – 1783)

The Vietnam War is also known as the Second Indochina War (the First Indochina War occurred between 1946 and 1954). Within Vietnam, the war is often referred to as either the “American War” or the “Resistance War against America”. Struggling U.S forces withdrew from the Vietnam War amid growing pressure from the American public which increasing opposed their country’s involvement in the war.

1. Battle of Guadalcanal (World War II) (1942 – 1943)
   Mexican-American War (1846 – 1848)
2. English Civil War (1642 – 1651)
   Battle of Tours (Umayyad invasion of Gaul) (732)

In 1836, the Republic of Texas gained independence from Mexico and was formally annexed by the U.S. in 1845. That action, plus the U.S.’s move to acquire more land, led to the Mexican-American war, in which Mexico lost roughly one-third of its territory (including most of California, Utah, Nevada, Arizona and New Mexico) to the U.S. The Mexican-American War was the first war America fought on foreign soil.

1. Battle of Tours (Umayyad invasion of Gaul) (732)
   The Tet Offensive (Vietnam War) (1968)
2. Thirty Years' War (1618 – 1648)
   Falkland Islands War (1982)

The Thirty Years’ War was, in fact, a series of wars fought by various forces and for a variety of causes. It is called a religious war because the initial hostilities were between Protestant and Catholic states. On average, estimates of the death toll as a result of Europe’s Thirty Years’ War put the figure at around 8 million.

1. Invasion of Normandy (World War II) (1944)
   Quasi-War (1798 – 1800)
2. Dungan Revolt (Hui Minorities' War) (1862 – 1877)
   Battle of the Nile (French Revolutionary Wars) (1798)

Just as the Russian victory in the Battle of Stalingrad (1942-43) stopped the German forces on the Eastern front, so did the Invasion of Normandy halt German’s advance on the Western front. The invasion began on June 6, 1944 (D-Day) and lasted until mid-July with over 1 million Allied troops landing on the beach in Normandy (northern France) during that time.

1. French & Indian War (1754 – 1756)
   Hundred Years' War (1337 – 1453)
2. Nigerian Civil War (1967 – 1970)
   Battle of Austerlitz (Napoleonic Wars) (1805)

Nigeria gained independence from the United Kingdom in 1960 and by 1967, several states in its Eastern Region declared their own independence from Nigeria. The new (short-lived) nation was called the Republic of Biafra, and Nigeria’s attempt to reunite the country resulted in the Nigerian Civil War (also known as the Biafran War). Some estimates say as much as 2 million civilians died of starvation, plus there were widespread reports of genocide.

1. Soviet War in Afghanistan (1979 – 1989)
   Battle of the Bulge (World War II) (1944)
2. First Arab-Israeli War (1948 – 1949)
   Battle of Cajamarca (Spanish conquest of Peru) (1532)

The term “bulge” refers to the marked swelling in the German front lines following their surprise attack on Allied (mostly American) forces in the Ardennes region of Europe. The attack began on December 16, 1944 and by its end on January 25, 1945 there was heavy loss of life on both sides plus a serious depletion of German armored forces.

1. Pequot War (1634 – 1638)
   Chinese Civil War (1927 – 1950)
2. English Civil War (1642 – 1651)
   Battle of Marathon (Greco-Persian War) (490 BCE)

The Battle of Marathon was fought between the Athenian army and a large invading Persian force. The battle is famous for the tale of Pheidippides, who it is said ran the first “marathon” (140 miles from Marathon to Athens) to proclaim Greek victory, then tragically collapsed and died from exhaustion.

1. World War I (1914 – 1918)
   Battle of Stalingrad (World War II) (1942)
2. Battle of Waterloo (Napoleonic Wars) (1815)
   War of a Thousand Days (1899 – 1903)

British and Prussian forces defeated Napoleon Bonaparte's troops on June 18, 1815 in the Battle of Waterloo. At the time, the location was a part of the United Kingdom of the Netherlands but it is now a part of modern-day Belgium. This was Napoleon’s final battle and the beginning of the end of the 20-year Napoleonic Wars.

1. Chinese Civil War (1927 – 1950)
   Battle of Huaihai (Chinese Civil War) (1948 – 1949)
2. World War II (1939 – 1945)
   American Civil War (1861 – 1865)

The American Civil War was fought between the Confederate States of the South (who advocated for slavery) and the Union States of the North (who opposed it). The war started shortly after Abraham Lincoln became the nation’s 16th President. It claimed almost 800,000 lives including that of the president, who was assassinated less than one month before the war officially ended.

1. Iran–Iraq War (1980 – 1988)
   Napoleonic Wars (1803 – 1815)
2. Battle of Austerlitz (Napoleonic Wars) (1805)
   Spanish-American War (1898)

The Iran-Iraq War began on September 22, 1980 with Iraq’s invasion of Iran. It ended 8 years later on August 20, 1988 thanks to a ceasefire negotiated by the United Nations. By the end of the war, over 1 million military and civilian deaths were recorded.

1. Second Sino-Japanese War (1937 – 1945)
   Battle of Guadalcanal (World War II) (1942 – 1943)
2. Dungan Revolt (Hui Minorities' War) (1862 – 1877)
   Quasi-War (1798 – 1800)

The Quasi-War was fought between France and the newly formed United States of America. The term “quasi” is used because neither of the two nations officially declared that it was at war with the other. The Quasi-War is distinguished by several facts, including that it was America’s first conflict and that it was fought entirely at sea.

1. Surrender at Yorktown (American Revolutionary War) (1781)
   Chinese Civil War (1927 – 1950)
2. French Revolutionary Wars (1792 – 1802)
   French and Indian War (1754 – 1756)

Mass atrocities and heavy civilian causalities were two of the main characteristics of the Chinese Civil War. The decades-long conflict saw the forces which were aligned to the Communist Party of China emerging victorious over those forces which were loyal to the Kuomintang or Nationalist Party of China.

1. Spanish-American War (1898)
   Thirty Years' War (1618 – 1648)
2. Spanish conquest of the Aztec Empire (1519 – 1521)
   Hundred Years' War (1337 – 1453)

The quest for Cuban independence was at the heart of the 4-month-long Spanish-American War between Spain and the U.S. The war, which ended in a U.S. victory, was fought over assets in the Caribbean and the Pacific. Upon defeat, Spain handed over control of Cuba, Puerto Rico, Guam and the Philippine Islands to the U.S.

1. World War I (1914 – 1918)
   French and Indian War (1754 – 1756)
2. Battle of Gettysburg (American Civil War) (1863)
   Invasion of Normandy (World War II) (1944)

The French and Indian War was fought between French and English forces over disputed colonial territories in North America. The name “French and Indian War” refers to the enemies of the English (who themselves had support from some Native American tribes). After two years, the war expanded to Europe and several other colonial territories around the world and become the Seven Years’ War.

1. World War II (1939 – 1945)
   Battle of Huaihai (Chinese Civil War) (1948 – 1949)
2. Dungan Revolt (Hui Minorities' War) (1862 – 1877)
   Battle of Cajamarca (Spanish conquest of Peru) (1532)

The Second World War was the deadliest and most widespread of any war in the history of mankind. All of the nations considered to be the world’s great powers took part. The war resulted in what some estimate to be 85 million deaths – including civilian victims of both the Holocaust and the nuclear bombings of Japan.

1. Surrender at Yorktown (American Revolutionary War) (1781)
   War of a Thousand Days (1899 – 1903)
2. English Civil War (1642 – 1651)
   Atomic Bombings of Japan (World War II) (1945)

The English Civil War consisted of a series of conflicts between supporters of the monarchy and supporters of the English and Scottish parliaments (among others). Charles I was king when the war began but by 1649 he was captured, convicted of high treason and executed. The war resulted in a parliamentarian victory but the monarchy was restored when Charles I’s son, Charles II, was made King of England in 1660.

1. Battle of Stalingrad (World War II) (1942)
   Phony War (1939 – 1940)
2. Napoleonic Wars (1803 – 1815)
   Soviet War in Afghanistan (1979 – 1989)

In August of 1942, Adolf Hitler’s forces attacked the city of Stalingrad (now Volgograd) – first from the air and then with huge numbers of infantry. The siege lasted for nearly six months before the invaders were forced to surrender in February of 1943 due, in part, to heavy losses and low food supply.

1. Mexican-American War (1846 – 1848)
   Battle of Tours (Umayyad invasion of Gaul) (732)
2. Battle of Cajamarca (Spanish conquest of Peru) (1532)
   Battle of Britain (World War II) (1940)

Although it is called a “battle,” this encounter was really an ambush of the Incan ruler Atahualpa, in the great plaza of the city of Cajamarca (in what is now Peru). The small band of armed Spanish troops, led by conquistador Francisco Pizarro, managed to kill thousands of unarmed Incan nobilities in the ambush.

1. Second Sino-Japanese War (1937 – 1945)
   American Revolutionary War (1775 – 1783)
2. Invasion of Normandy (World War II) (1944)
   Nigerian Civil War (1967 – 1970)

The American Revolutionary war between Great Britain and the Thirteen Colonies led to the birth of a nation which would go on to become one of the world’s superpowers. The war expanded into a global conflict with France and Spain among those joining in to fight British forces and disrupt British interests in the Caribbean, India and Europe.

1. Vietnam War (1955 – 1975)
   Battle of Hastings (Norman conquest of England) (1066)
2. Spanish conquest of the Aztec Empire (1519 – 1521)
   Battle of Austerlitz (Napoleonic Wars) (1805)

The Battle of Austerlitz took place on December 2, 1805. It is generally regarded as Napoleon Bonaparte’s greatest victory in the 12-year long Napoleonic Wars. It is also known as the Battle of the Three Emperors since it involved Napoleon (Emperor of France) leading his forces against those of Tsar Alexander I (Emperor of Russia) and Holy Roman Emperor Francis II (later called Emperor of Austria).

1. American Civil War (1861 – 1865)
   French Revolutionary Wars (1792 – 1802)
2. Battle of Britain (World War II) (1940)
   Battle of Tours (Umayyad invasion of Gaul) (732)

Moorish General Abd-er Rahman led a Muslin army on an invasion of Tours, France with the hope of moving onward throughout Europe. Charles Martel (the Duke and Prince of the Franks) who was also known as “’The Hammer” and his largely unarmored Frankish army managed to capture and kill General Abd-er Rahman and turn back the invaders.

1. Siege of Orleans (Hundred Years’ War) (1429)
   Korean War (1950 – 1953)
2. Second Congo War (1998 – 2003)
   Battle of Huaihai (Chinese Civil War) (1948 – 1949)

The Second Congo War lasted just 2 weeks short of 5 years. It started in the Democratic Republic of Congo shortly after the7-month-long First Congo War ended. The war, which is sometimes referred to as the Great War of Africa, involved 9 African countries and left approximately 5.4 million people dead.

1. World War II (1939 – 1945)
   Phony War (1939 – 1940)
2. Iran–Iraq War (1980 – 1988)
   Pequot War (1634 – 1638)

World War II began with Germany’s invasion of Poland on September 1, 1939 and the formal declaration of war by the U.K. and France two days later. Following this, however, there were six to eight months of relative inactivity which prompted some news outlets to label this period as the Phony War (often spelt “Phoney”). Other names used were the “Twilight War,” the “Sitting War” and the “Strange War.”

1. Battle of Stalingrad (World War II) (1942)
   Vietnam War (1955 – 1975)
2. First Arab-Israeli War (1948 – 1949)
   Napoleonic Wars (1803 – 1815)

Napoleon Bonaparte led the French Empire through as many as 60 battles against various coalitions of European powers. He lost just 7 of these battles but eventually lost the war. He was captured and exiled twice – first to the island of Elba in 1814 and then to the island of St. Helena in 1815. Some estimates put the death toll resulting from the Napoleonic Wars at around 6 million.

1. Battle of the Bulge (World War II) (1944)
   War of 1812 (1812 – 1815)
2. World War I (1914 – 1918)
   Falkland Islands War (1982)

From July 28, 1914 to November 11, 1918 (4 years, 3 months and 2 weeks), a war which originated in Europe engulfed the globe, leading to the death of approximately 18 million people. The fighting ended with the signing of an armistice at 11 a.m. on November 11, 1918 (“the eleventh hour of the eleventh day of the eleventh month”). The Treaty of Versailles, signed on June 28, 1919, formally ended the war.

1. Russian Civil War (1917 – 1922)
   Battle of Marathon (Greco-Persian War) (490 BCE)
2. Atomic Bombings of Japan (World War II) (1945)
   Gulf War (1990 – 1991)

In the years immediately following the Russian Revolution, between 7 and 12 million people died in the Russian Civil War, which was fought in what was then the Russian Empire. The war was characterized by both the Red Terror and the White Terror, in which the opposing sides conducted mass killings of their enemies, their enemies’ supporters and those who would not fight.

1. Battle of Gettysburg (American Civil War) (1863)
   Falkland Islands War (1982)
2. The Tet Offensive (Vietnam War) (1968)
   Seven Years' War (1756 – 1763)

The Seven Years’ War grew out of the French and Indian War which began in North America (1754) between French and English forces. It is often regarded as the first ever global war with conflicts in several locations around the world, including Europe, the Americas, India, West Africa and the Philippines. All major European countries joined in the war, aligning themselves with either the French or English cause.

1. Pequot War (1634 – 1638)
   Battle of Guadalcanal (World War II) (1942 – 1943)
2. Chinese Civil War (1927 – 1950)
   Nigerian Civil War (1967 – 1970)

Pequot War was fought mainly between two Native American tribes – the Pequot and the Mohegan. At the heart of their dispute was the quest for political power including who had trading rights with the newly arrived Europeans. The English sided with the Mohegan while the Dutch, at first, aligned themselves with the Pequot. The war resulted in a decisive defeat of the Pequot and the near elimination of their tribe.

1. Second Congo War (1998 – 2003)
   Korean War (1950 – 1953)
2. Battle of the Nile (French Revolutionary Wars) (1798)
   Hundred Years' War (1337 – 1453)

The Battle of the Nile was a naval conflict which took place on Egypt’s Mediterranean coast. It lasted from August 1 – 3, 1798 and resulted in the British Royal Navy successfully stopping Napoleon’s Navy of the French Republic from invading Egypt. Napoleon had plans to follow up this offensive with a move against British interests in India.

1. The Tet Offensive (Vietnam War) (1968)
   Quasi-War (1798 – 1800)
2. American Revolutionary War (1775 – 1783)
   Thirty Years' War (1618 – 1648)

The Tet Offensive began on January 30, 1968 during the Vietnamese New Year or “Tet.” It involved a series of surprise attacks by North Vietnamese forces against military and civilian locations of the South Vietnamese Army, as well as American and allied forces. The Tet Offensive marked the beginning of the decline of public support in the U.S. for the Vietnam War.

1. Battle of Hastings (Norman conquest of England) (1066)
   Surrender at Yorktown (American Revolutionary War) (1781)
2. Siege of Orleans (Hundred Years’ War) (1429)
   Russian Civil War (1917 – 1922)

American forces (led by George Washington) and a French naval fleet worked together to hand the British Army a crucial defeat at Yorktown, Virginia. The intense battle lasted from September 28 – October 19, 1781. The Surrender at Yorktown goes by several names, including “German Battle” because of the large numbers of German soldiers in each of the three armies.

1. Iran–Iraq War (1980 – 1988)
   Gulf War (1990 – 1991)
2. Phony War (1939 – 1940)
   French Revolutionary Wars (1792 – 1802)

The French Revolution began in 1789 and led to the abolition of the French monarchy in 1791. The French Revolutionary Wars were fought on a global scale between the new French Republic and the remaining European monarchies. France’s success in the conflict encouraged the spread of revolutionary ideals among the common people of Europe.

1. Battle of Austerlitz (Napoleonic Wars) (1805)
   Battle of Britain (World War II) (1940)
2. Spanish-American War (1898)
   French and Indian War (1754 – 1756)

The aerial Battle of Britain between the U.K.’s Royal Air Force (RAF) and the German Air Force (Luftwaffe) lasted for almost 4 months (July 10 – October 31, 1940). The battle led into what became known as the Blitz – heavy and sustained nighttime bombing of cities in the U.K. from September 7, 1940 to May 11, 1941.

1. War of 1812 (1812 – 1815)
   Battle of Waterloo (Napoleonic Wars) (1815)
2. Mexican-American War (1846 – 1848)
   Soviet War in Afghanistan (1979 – 1989)

Also called the Soviet-Afghan War, this conflict took place entirely within Afghanistan. The war involved Soviet forces and the Afghan government on one side and the insurgent mujahideen (backed by the U.S. and Pakistan) on the other. It resulted in close to 2 million civilian deaths and the dislocation of millions of Afghans who sought refuge in neighboring countries, such as Iran and Pakistan.

1. Battle of the Nile (French Revolutionary Wars) (1798)
   American Revolutionary War (1775 – 1783)
2. Battle of Huaihai (Chinese Civil War) (1948 – 1949)
   Battle of Waterloo (Napoleonic Wars) (1815)

Also called Battle of Hsupeng and the Huaihai Campaign, the Battle of Huaihai took place between November, 1948 and January, 1949 close to the end of the Chinese Civil War. The Chinese Communist Party emerged victors in this battle which played a vital role in their victory in the war at large against the Kuomintang or Nationalist Party of China.

1. Atomic bombings of Japan (World War II) (1945)
   Seven Years' War (1756 – 1763)
2. Siege of Orleans (Hundred Years’ War) (1429)
   English Civil War (1642 – 1651)

The first and only use, to date, of nuclear weapons in warfare took place on August 6 and 9, 1945. On the first day, the Enola Gay, a U.S. superfortress bomber, dropped a 9,700-pound atomic bomb (codename: Little Boy) on Hiroshima. Three days later, a B-29 bomber dropped "Fat Man," a 10,300-pound atomic bomb on Nagasaki. World War II ended six days later when Japan surrendered – August 15, 1945.

1. Mexican-American War (1846 – 1848)
   Seven Years' War (1756 – 1763)
2. Quasi-War (1798 – 1800)
   Battle of Guadalcanal (World War II) (1942 – 1943)

Guadalcanal in the British Solomon Islands was the location of the Allied forces’ first military offensive (by land, sea or air) against the forces of the Empire of Japan. Also called the “Guadalcanal Campaign,” the fighting lasted from August 7, 1942 to February 9, 1943, and ended in an Allied victory. It marked the beginning of Allied domination in the Pacific Theatre of WWII.

1. Second Sino-Japanese War (1937 – 1945)
   Russian Civil War (1917 – 1922)
2. Battle of Marathon (Greco-Persian War) (490 BCE)
   Nigerian Civil War (1967 – 1970)

The Second Sino-Japanese war amassed a total of 30 million deaths, by some estimates. This number is far greater than the approximately 50,000 counted as dead in the First Sino-Japanese War, fought between July, 1894 and April, 1895. The Second Sino-Japanese War is credited by some as being the true beginning of World War II – as opposed to Nazi Germany’s invasion of Poland in September of 1939.

1. Surrender at Yorktown (American Revolutionary War) (1781)
   War of 1812 (1812 – 1815)
2. First Arab-Israeli War (1948 – 1949)
   American Civil War (1861 – 1865)

The First Arab-Israeli War is the earliest in a series of wars commonly referred to in plural as the Arab-Israeli Wars. The most significant of the conflicts occurred in 1948 – 49, 1956, 1967, 1973 and 1982. The tensions and conflicts between the two sides continue into the present day.

1. Second Congo War (1998 – 2003)
   Hundred Years' War (1337 – 1453)
2. Korean War (1950 – 1953)
   Battle of Britain (World War II) (1940)

The Hundred Years’ War actually lasted for 116.5 years – from May 24, 1337 to October 19, 1453. It was fought primarily between the Kingdoms of England and France over who had rights to the French throne. It consisted of a series of minor wars which eventually led to victory for the French and the beginning of the War of the Roses, in which claim to the English throne was now being disputed.

1. Thirty Years' War (1618 – 1648)
   French Revolutionary Wars (1792 – 1802)
2. Spanish conquest of the Aztec Empire (1519 – 1521)
   Battle of Gettysburg (American Civil War) (1863)

The Spanish conquest of the Aztec Empire is recorded as one of the costliest conflicts in history in terms of the number of persons killed. As part of the early European efforts at colonization of the Americas, it resulted in approximately 24.5 million deaths. The Spaniards were aided in their defeat of the Aztecs by several other indigenous groups.