The Crusades - why they happened, and what they actually achieved

By Chris Livemore

We've all heard of the Crusades but how much do you actually know about them?

There is a moment in Crusader history that tells you almost everything you need to know about the Crusades. In 1204, the Fourth Crusade arrived not at Jerusalem, which had been its stated objective, but at Constantinople, one of the greatest Christian cities in the world. The Crusaders stormed it, looted it, and left behind destruction so extensive that relations between Eastern and Western Christianity never fully recovered.

A military expedition launched to defend Christianity had ended up attacking fellow Christians.

If that sounds complicated, that's because the Crusades were complicated. They lasted nearly two hundred years. They involved popes, kings, merchants, pilgrims, soldiers, and ordinary families. They produced acts of extraordinary courage, extraordinary faith, and extraordinary brutality, sometimes all at the same time and with equal measure.

So why did they happen?

The world before the Crusades

To understand the Crusades, you have to begin with the eastern Mediterranean in the late eleventh century. For centuries, Christian pilgrims had travelled to Jerusalem, one of the holiest cities in Christianity. The city had been under Muslim rule since the seventh century, but pilgrimage generally remained possible.

The situation became more unstable after the rise of the Seljuk Turks. In 1071, the Byzantine Empire suffered a major defeat at the Battle of Manzikert and lost much of Anatolia - modern-day Turkey. The empire's rulers became increasingly concerned about their ability to defend their territory.

In 1095, the Byzantine emperor Alexios I Komnenos appealed to Western Europe for military assistance. His request reached Pope Urban II. At the Council of Clermont later that year, Urban called on Western Christians to aid their fellow Christians in the East and help secure access to the holy places associated with the life of Christ.

The response was extraordinary. Thousands of people decided to go and fight.

Why did people join the Crusades?

There is no single answer. Some joined out of genuine religious conviction. Medieval Europe was deeply religious, and many Crusaders believed they were undertaking an act of devotion. Others hoped for adventure, status, or financial opportunity.

Younger sons of noble families sometimes saw the East as a place where they might acquire land or reputation. Knights were promised spiritual rewards by the Church. Some participants were undoubtedly motivated by a mixture of faith and self-interest.

The First Crusade

Against almost all expectations, the First Crusade succeeded. After a difficult journey across Europe and Asia Minor, Crusader armies captured Jerusalem in 1099.

The victory came at a terrible cost. Contemporary sources describe large-scale killings following the city's capture, including Muslim and Jewish inhabitants. In the aftermath, Crusaders established a series of states in the eastern Mediterranean, including the Kingdom of Jerusalem.

For a time, it appeared that the Crusading project might succeed. European knights settled in the region. Castles were built. Trade expanded. New political alliances emerged. But maintaining these territories proved far harder than conquering them.

Saladin and the loss of Jerusalem

The most famous figure of the Crusading era was almost certainly Saladin. In 1187, his forces defeated the Crusader army at the Battle of Hattin and recaptured Jerusalem.

The loss shocked Europe.

It inspired the Third Crusade, led by some of the most powerful rulers in Christendom, including Richard I - you may know him as Richard the Lionheart. Although Richard won several important victories, he never retook Jerusalem. Instead, he negotiated an agreement that allowed Christian pilgrims access to the city. It was not the triumph many Crusaders had hoped for, but it prevented a complete collapse of the remaining Crusader territories.

Then things went wrong

The later Crusades are a reminder that history rarely follows a tidy script. The Fourth Crusade famously ended with the sack of Constantinople in 1204. Other expeditions targeted Egypt, North Africa, and different parts of the eastern Mediterranean with mixed results.

Some campaigns achieved temporary successes. Many failed.

Political rivalries, financial problems, poor planning, and competing ambitions frequently undermined the original goals of the expeditions. By 1291, the last major Crusader stronghold at Acre had fallen. The Crusader states were gone. The era of large-scale Crusading in the Holy Land had effectively come to an end.

Were the Crusades worth it?

That depends entirely on who you ask. For many Crusaders, the campaigns represented acts of faith and sacrifice. For merchants in cities such as Venice and Genoa, the Crusading era helped expand commercial connections across the Mediterranean.

For Byzantine Christians, the Fourth Crusade was a catastrophe. For Muslim communities who experienced invasion, warfare, and massacre, the memory of the Crusades was understandably very different from the stories told in medieval Western Europe. Historians still debate the long-term consequences.

The Crusades encouraged greater contact between Europe and the eastern Mediterranean. They contributed to trade, diplomacy, cultural exchange, and the movement of ideas. They also left behind deep divisions, enormous loss of life, and centuries of mistrust. The truth is that the Crusades were neither a glorious adventure nor a simple story of villains and heroes.

They were a human story. There were between 5-9 million deaths as a result of the Crusades between 1095 and 1291 depending upon the research you use. That’s an awful lot of deaths.

The Crusades were messy.