The Longest War in History Lasted 781 Years

It wasn’t one dramatic battle that dragged on for centuries. It was a long, messy grind across the Iberian Peninsula, where control shifted, borders hardened, and everyone kept fighting even when the “front line” moved.

In 711, Tariq ibn Ziyad’s Berber forces crossed into the Visigothic kingdom, and within seven years much of Spain and Portugal fell under Muslim rule, with Cordoba becoming a major learning hub. Then Pelagius showed up in the north, beating a small Muslim force at Covadonga in 718 or 722, and that spark turned into a slow push south: Toledo in 1085, Lisbon in 1147, Cordoba in 1236, Seville in 1248, and finally Granada, held out until January 2, 1492.

The wild part is that the “longest war” ends just before the same rulers back Columbus, like the calendar itself got bored of separating history from momentum.

What the Longest War in History Actually Was

In 711 CE, a Muslim Berber army under the general Tariq ibn Ziyad crossed the Strait of Gibraltar and invaded the Visigothic Kingdom that ruled what is now Spain and Portugal. Within seven years, most of the peninsula was under Muslim control. The new rulers founded the Umayyad Caliphate of Cordoba, which became one of the most sophisticated centers of learning in medieval Europe.

In 718 or 722, depending on whose chronology you trust, a Christian noble named Pelagius defeated a small Muslim force at the Battle of Covadonga in the northern mountains of Asturias. Historians treat that battle as the start of the Reconquista, even though most people involved would not have used that word for what they were doing.

The reconquest moved south in slow waves over the next 770-plus years. Toledo fell to Christian forces in 1085. Lisbon in 1147. Cordoba in 1236. Seville in 1248. Each generation pushed the line further, then settled in for decades or centuries before the next push. By the 1300s, only the small Emirate of Granada remained under Muslim rule, propped up by tribute paid to Christian kingdoms.

Granada fell on January 2, 1492, to the combined forces of Ferdinand and Isabella. The same monarchs funded Christopher Columbus's voyage later that year. The longest war in history ended ten months before the European discovery of the Americas, which is the kind of timeline that makes the human past feel like a different planet.

You can still visit the castles and fortified villages that were built and rebuilt across the peninsula during all this. Most Spanish hilltop towns trace their walls to one phase or another of the Reconquista.

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The moment Tariq ibn Ziyad’s army hits the Strait of Gibraltar, the clock starts ticking, and it never really stops.

Why Historians Argue About the Longest War

There are three other serious contenders for the title, and each one shows how slippery "longest war" really is as a category.

The first is the Three Hundred and Thirty-Five Years' War between the Netherlands and the Isles of Scilly, a small archipelago off the coast of Cornwall. The Dutch declared it in 1651 during the English Civil War. Nobody actually fought.

The declaration was forgotten on both sides until 1986, when a Scilly historian discovered the documents and arranged a formal peace treaty. Technically it lasted 335 years. Practically, it was a paperwork problem.

The second is the Roman-Persian wars, fought intermittently between Rome and various Persian dynasties for roughly 700 years from 92 BCE to 628 CE. The catch is that historians usually treat these as a series of separate wars, not one continuous conflict, because the political entities on both sides kept changing. Rome became Byzantium. Parthia became the Sassanid Empire. The framing of "the same war" requires squinting.

The third is the Hundred Years' War between England and France, which is famously not 100 years. It ran from 1337 to 1453, a stretch of 116 years, and even that span includes long periods of truce. Compared to the Reconquista, it is short. Compared to a modern war, it is unimaginable.

The shape of the disagreement is the same one most history myths get tripped up on. Dates that look clean in a textbook turn out to depend on which scholar drew the line and what they chose to include.

What Was the Longest War in US History

For American context, the longest war in US history is the war in Afghanistan, which ran from October 7, 2001, to August 30, 2021. Nearly 20 years. It overtook the Vietnam War as the United States's longest conflict in 2010, then kept going for another decade.

According to Britannica, more than 2,400 American service members were killed in Afghanistan, with around 20,700 wounded. Coverage by NPR at the time of the withdrawal put the same figure at 2,400-plus US military deaths, alongside tens of thousands of Afghan deaths.

Vietnam, by comparison, lasted 17 years and four months and cost the US around 58,000 military deaths. The Iraq War, often paired with Afghanistan in public memory, ran for eight years and nine months.

Twenty years is short by Reconquista standards. It is long by every other.

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When Pelagius wins at Covadonga, it’s not the end of anything, it’s the beginning of a decades-long habit of pushing and pausing.

It also echoes the Roanoke colonists, where 117 settlers vanished after carving “CROATOAN”.

Once Toledo falls in 1085 and Lisbon follows in 1147, the Reconquista starts looking less like a single war and more like a series of “we’ll see you again” campaigns.

What About the Longest Civil War in History

The longest civil war in history is usually given as the Karen conflict in Myanmar, which began in 1949 and is still active as of 2025. That's over 75 years. Other long civil wars on similar lists include the Burmese conflict more broadly, which has involved dozens of ethnic armed groups since independence, and various intermittent rebellions in Africa and South America that span generations.

Civil war is even harder to define cleanly than international war. The fighting in Myanmar has gone through multiple regimes, ceasefires, and reorganizations of the armed groups involved. But the core grievance, recognition of ethnic minority autonomy, has remained roughly constant since 1949, which is why historians count it as one ongoing conflict.

After Granada falls on January 2, 1492, the story doesn’t just wrap up, it immediately links up to Ferdinand and Isabella funding Columbus later that year.

Why "Longest War" Is a Slippery Question

Wars don't always start when they're declared. They don't always end when peace is signed. The Reconquista's start date is debated. The Anglo-French rivalry between England and France ran across centuries through different named wars and is sometimes treated as a single "Second Hundred Years' War." The Cold War is sometimes counted as a 45-year war that nobody officially declared.

What makes the Reconquista the standard answer is that the same broad goal, Christian reconquest of Iberia, ran from 711 to 1492 with no period where it was abandoned by both sides. Wars don't last that long anymore. The infrastructure of the modern state, plus the way modern media compresses public attention, makes 20-year wars feel endless.

Eight-century wars belong to a world that no longer exists. They also produced consequences that lasted, including centuries-deep marks on European geography that the medieval period left on everything from town layouts to medical practice.

The shortest war in history, by contrast, took 38 minutes.

The Reconquista ends on January 2, 1492, but the real plot twist is how fast Europe turns around and charges into the next one.

For another unbelievable stretch of time, watch Cleopatra’s four-hour epic and other runtime monsters.