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The Long and Winding Road: History‘s Most Enduring Military Conflicts

War has been a constant companion of human civilization dating back to prehistory when competing tribes first clashed over territory and resources. Most wars conclude fairly swiftly within a span of months or a few years. However, a number of complex geopolitical, religious and succession disputes throughout history have fueled wars persisting for decades or even centuries.

These protracted conflicts extract an enormous human toll and place great economic strain on the participating nations. Still, leaders often find it difficult to withdraw without achieving their strategic objectives. As a result, generations of soldiers and civilians get caught up in the seemingly never-ending violence.

This article will chronicle history’s lengthiest military engagements that raged on for half a century or longer. We’ll analyze their root triggers, costs and cultural impacts.

Defining a "Long War"

For this discussion, we’ll classify "long wars" as those lasting a minimum 50 years with intermittent periods of active combat between clearly defined opponents. Naturally, most long wars aren’t continuously fought for their entire duration but rather encompass a series of smaller conflicts tied to an overarching theme.

Protracted wars usually start out focused on tangible objectives like conquering territory, securing succession rights or establishing economic control. However, they often take on expanded religious, ethnic and ideological dimensions the longer they drag on. This tends to perpetuate the cycle of violence despite the original casus belli losing relevance.

Costs of Endless Warfare

Wars lasting multiple generations place a massive burden on economies and societies. Long wars necessitate maintaining large standing armies and continually acquiring provisions/matériel to sustain the fighting.

High casualty rates also take an immense demographic toll that can retard post-war recovery. And the uncertainty of endless conflict discourages trade, investment and development.

For example, the grueling Thirty Years’ War (1618-1648) thoroughly devastated Germany, causing lasting economic damage and a population decline of over 15% across the Holy Roman Empire.

Sparking the Fuse

While each long war arose from unique circumstances, we can identify several consistent triggers:

Imperial Conquest: Emperor Augustus launched Rome’s 200-year conquest of Hispania in 218 BCE seeking new lands to fuel the Republic’s expansion. The French similarly invaded Algeria in 1830 with dreams of colonial domination in Africa.

Dynastic Disputes: The 1337-1453 Hundred Years’ War centered on England’s claims to the French throne and related succession questions. Meanwhile, the 1568-1648 Eighty Years’ War was partly ignited by Spanish King Phillip II inheriting the throne instead of a Portuguese heir.

Economic Interests: The Dutch revolted against their Habsburg Spanish overlords in 1568 partly to gain control over the lucrative Baltic maritime trade routes. Commercial considerations also prompted the Dutch-Portuguese War (1602-1661) as the Dutch East India Company tried to dominate the spice trade by force.

Religious Divisions: The 1096-1291 Crusades sought to conquer Muslim-controlled Jerusalem for Christendom, revealing deep schisms between the two faiths. Religious differences between Protestants and Catholics likewise intensified the bitterness of the Thirty Years’ War.

Ethnic Tensions: Ethnic hatreds and massacres escalated the ferocity of Russo-Circassian War (1763-1864) as the Tsarist Empire sought to fully conquer the Caucuses mountain tribes after centuries of resistance.

Ideological Conflicts: Capitalism clashed with Communism across frozen mountain terrain during the Cold War as the US and USSR fought a 40-year proxy war for influence over Afghanistan. Each side armed opposing Afghan factions, prolonging the misery.

Now let’s take a deeper look at history’s most remarkable multi-generational military struggles:

1. The Reconquista (718-1492) – 774 Years

The small Iberian kingdom of Asturias fought the longest war in history when it launched the 722 AD Siege of Covadonga against the ruling Umayyad Muslin Caliphate. This surprise attack ignited the 774-year Reconquista as Christian armies gradually pushed their Muslim rivals off the peninsula.

The Reconquista didn’t progress steadily southwards year-to-year. Instead, it encompassed an intermittent series of battles, truces, shifty alliances and betrayals as small Portuguese, Leonese and Castilian fiefdoms coalesced into the kingdoms that would become modern Spain.

The epic conflict finally concluded in 1492 when Queen Isabella I of Castile and King Ferdinand II of Aragon conquered Granada – the last Muslim enclave on the peninsula. Spain‘s hard-fought victory changed the religious dynamics of Europe and allowed its rulers to sponsor Christopher Columbus’ fateful 1492 expedition.

La Rendición de Granada showing the 1492 Spanish conquest of Granada
The 1492 Siege of Granada After 800 Years of Reconquista

2. Roman Conquest of Hispania (218 BCE–19 CE) – 237 Years

The vast riches and fertile farmland of the Iberian Peninsula enticed Rome to launch a ruthless 200+ year campaign to absorb modern-day Spain and Portugal into its sprawling Republic.

Rome initiated the invasion after the Second Punic War against rival superpower Carthage for control of strategic Mediterranean trade routes. But Rome likely had its eyes on seizing the silver mines and olive groves of Hispania long before then.

The conquest began gradually in 218 BCE but soon necessitated genocidal tactics as stiff resistance emerged across the peninsula over the next two centuries. Eventually in 19 CE, Rome’s first emperor Caesar Augustus claimed to have finally subjugated all the Iberian tribes after massacring tens of thousands.

Integrating Hispania greatly enriched Rome’s coffers and gave it a strategic control over the western Mediterranean. But keeping its holdings required building 60 fortresses and deploying three full legions across conquered towns like Tarraco and Corduba to deter endemic rebellion.

3. The Crusades (1096-1291) – 195 Years

The Crusades erupted from Pope Urban II’s 1095 call for Western armies wrest Jerusalem and the Holy Lands from Muslim rule so that pilgrims could safely travel there. This appeal kindled religious fervor across European nobility who raised vast armies over eight major Crusades until finally relinquishing their small Levantine beachheads by 1291.

In the First Crusade alone, 100,000 eager volunteers marched 2,700 arduous miles to briefly capture Jerusalem in 1099 before being pushed back. Later Crusades were relatively smaller affairs as the Vatican consolidated its holdings rather than seeking to liberate new territory.

The bloody campaigns enabled the blossoming of trade between Europe, Egypt and Syria. But they failed their spiritual objectives long-term. Interestingly, the Fourth Crusade got diverted into the 1204 Sack of Christian Constantinople, revealing how mercurial and disorganized these "Holy" endeavors proved to be.

The Siege of Antioch During the First Crusade

The 1098 Siege of Antioch

4. The Hundred Years’ War (1337-1453) – 116 Years

This legendary conflict between France and England dominated 14th century Medieval Europe. The Hundred Years’ War centered on various English monarchs pressing claims over French territory based on complex succession laws tied to William the Conqueror’s 1066 Norman Conquest.

Major battles like the 1346 English victory at Crécy and the 1415 Battle of Agincourt where English longbows decimated French knights entered popular legend. Charismatic figures like French heroine Joan of Arc and robber baron Sir John Hawkwood emerged from the chaos.

Strategically, the war proved indecisive. England managed to control large swaths of France at times but couldn’t make gains permanent or seize Paris outright. Bitter fighting ended after the 1453 French conquest of English-ruled Bordeaux.

The English and French royal houses resolved to end such debilitating warfare, paving the path for the eventual Tudor alliance of Henry VIII and Francis I in 1520.

Hundred Years' War Battle Collage

5. The Sengoku Period (1467-1615) – 148 Years

"Sengoku" translates to "Warring States", perfectly describing Japan’s turbulent 15th to 17th century carved up between the Kamakura and Tokugawa Shogunates. During this lawless epoch, provincial Daimyo warlords and Samurai retinues endlessly battled for land and authority.

The Onin War (1467-1477) triggered the chaos by pegging rival Yamana and Hosokawa clans against each other over Ashikaga family succession. Regional violence swiftly spread, devastating local economies.

Three skilled leaders briefly imposed stability with iron-fisted rule only to see anarchy emerge after their deaths. First came ruthless conqueror Oda Nobunaga who ruled much of Honshu before a rebel ambush in 1582. Toyotomi Hideyoshi proceeded to reunify Japan but his 1600 death and son’s incompetence renewed turmoil. Finally, cunning Tokugawa Ieyasu maneuvered rivals into submission and founded a Shogunate in 1603 that governed Japan for the next 250 years.

6. Second Hundred Years’ War (1689-1815) – 126 Years

This term groups the near-continuous wars fought by European superpowers Britain and France between 1689-1815 as they vied to fill the power vacuum left by a declining Habsburg Spain.

The Nine Years War, War of Spanish Succession, War of Austrian Succession, Seven Years War and culminating Napoleonic Wars all formed part of this Second Hundred Years’ War. Geopolitically, Britain sought to check French hegemony in Western Europe and protect its commercial maritime interests.

France arguably gained advantage by keeping continental Europe in constant upheaval. But Britain helped fund coalition efforts that defeated ambitious French Emperor Napoleon at Waterloo in 1815, restoring peace.

Tactical developments like British naval dominance and mass French conscription caused mass casualties during this volatile epoch with Britain alone losing over 300,000 sailors during the Napoleonic Wars. The turmoil also fostered resentment over monarchical rule that fueled liberal revolutions across Europe.

7. Conquest of Transoxiana (673-751 CE) – 78 Years

The Abbasid Revolution in the Middle East sparked an 8th century pan-Islamic crusade to absorb the vast Central Asian region of Transoxiana into the Caliphate. The territory encompassed rich oasis-fed cities controlling Silk Road trade like Samarkand, Bukhara and Tashkent falling in modern Uzbekistan/Tajikistan.

Initial Arab raids seeking booty began penetrating the region from 673 CE onwards. But after toppling the Umayyads and establishing the Abbasid Caliphate in 750 CE, conquering Transoxiana militarily and converting it religious became major priorities. The new Abbasid governor Abu Muslim dispatched forces that captured key cities until the last Sogdian and Turkic defenders were defeated by 751 CE.

Conquering Transoxiana brought enormous tax revenues and trade profits into Abbasid coffers, helping fund the Islamic Golden Age. But it also diffused their power by requiring troops permanently encamped in distant cities suppressing revolts instead of securing the Caliphate heartland. That vulnerability assisted Persian and Mongol invasions in later centuries.

8. Eighty Years War (1568-1648) – 80 Years

Also called the Dutch Revolt, the Eighty Years War secured independence for the protestant Dutch provinces of the Low Countries seeking religious freedom and economic prosperity safe from Spanish Catholic domination.

Conflict flared on and off for decades as heirs of the Burgundian and Habsburg dynasties exerted control over the patchwork of Dutch and Flemish counties. Discontent simmered and finally exploded in 1568 when iron-fisted Spanish King Phillip II installed his half-brother Don Fernando as viceroy over the region sparking an uprising.

Celebrated Dutch leaders like William of Orange then led a resilient revolt repulsing multiple Spanish attempts to re-subjugate the protestant provinces. Savage fighting saw Antwerp and Haarlem utterly devastated before hostilities ceased with the 1648 Peace of Münster recognizing Dutch sovereignty.

The arduous conflict fostered Dutch nationalism, helping the unified provinces become history’s first parliamentary democracy guided by secularism and religious tolerance.

9. Byzantine-Arab Wars (634-1050) – 416 years

Soon after Prophet Muhammed’s passing, his Arab followers burst from their desert confines imbued with fiery crusading zeal to spread the new Islamic faith by sword and leverage immense wealth through conquest.

The Byzantine (Eastern Roman) Empire controlled the resource-rich, Christian Levant region and Anatolia standing firmly athwart ambitions to expand the Dar al-Islam (House of Islam). This irreconcilable religious clash over sacred lands helped fuel over four centuries of grueling territorial warfare.

The first major territorial clash saw Arab forces crush the Byzantines at 634’s pivotal Battle of Ajnadayn opening the door to their Syria conquest. Constantinople repelled desperate sieges in 674 and 717 before the 838 Amorium Massacre broke Byzantine resistance.

Crusader wars diminished the Caliphate allowing Byzantines brief respites. But the vigorous 1055-1060 invasion of Anatolia by Turkic nomads ended Constantinople’s regional dominance for good. The Byzantines limped on two more centuries before 1453’s tragic fall.

Byzantine Empire resisted Arab Conquests for 400+ years before Turkic tribes delivered the fatal blow

Map of Byzantine Losses to Muslim Powers Over Centuries

10. The Deluge & Northern Wars (1655-1660) – 405 Years

This entry combines two epic wars involving Polish-Lithuanian Commonwealth—one defensive and one expansionist. As Central Europe’s largest territory, the Commonwealth fought for its very existence against invading Sweden from 1655-60. It simultaneously tried expanding north into disputed Baltic lands sparking wars against Russia and Sweden until final defeat in 1710.

The “Swedish Deluge” subjugated the Commonwealth to occupy its lands and loot its treasures from 1655-1660. However Poland persevered and rebounded. Later, its aggressive King Stephen Báthory (1576-86) galvanized the Commonwealth seeking new conquests. This culminated in abortive efforts from 1563–1710 to absorb Livonia from the Swedish Empire that ended in catastrophic losses when Sweden counterattacked.


Hopefully this survey of history’s most remarkable multi-generational wars revealed how religious hostilities, dynastic disputes, imperial ambitions and ethnic tensions can sustain conflicts spanning decades or even centuries. The amount of blood and treasure sacrificed in prosecuting just one of these wars over its entire course often profoundly impacted the participating nations‘ later development and stability.

Yet despite the ravages inflicted during centuries of violence, humanity still couldn’t devise less destructive means of resolving entrenched geopolitical differences. Sadly enmity rooted in competing faiths and hunger for finite resources continues compelling nations to war without end even today.