On AskHistorians we often point out that it’s difficult or impossible to know why something didn’t happen. In this case, should the crusades have been successful? Successful at doing what? Why should there have been lasting change in the Middle East?

For medieval Christians of course the answer was clear - Jerusalem should be ruled by Christians, and for awhile they were willing to make the effort to get it back. But also, in this case, the reasons why something didn’t happen are relatively easy to figure out - Latin Christians from Western Europe realized, eventually, that crusading was a terrible idea. Aside from the first one, which the local Muslim rulers weren’t expecting, every crusade was a massive failure and a pointless waste of time, men, and money.

There were some long-lasting effects in the Middle East though, even if they weren’t what the crusaders had planned for. Prior to the First Crusade, the Near East was ruled by numerous minor Seljuk states, theoretically subject to the Great Seljuk sultan (and the Abbasid caliph) in Baghdad, but really independent. It took a few decades, but eventually all of Syria was united under one ruler (Nur ad-Din, and then his successor Saladin), in response to the presence of the crusader states on the coast.

Egypt was ruled by the Fatimid dynasty at the time, but it fell to Saladin in the 1170s. What was Saladin doing there? He was intervening there because the crusaders had invaded it. Would Syria and Egypt have been united if the crusaders weren’t meddling there? Maybe not.

Saladin and his family, the Ayyubid dynasty, took back Jerusalem in 1187, and they survived several more waves of crusades throughout the 12th and 13th centuries. The Ayyubid rulers of Egypt were then overthrown by their own slave-soldiers, the Mamluks, in 1250 - right in the middle of yet another crusade, this time led by Louis IX of France. Louis had actually been defeated and imprisoned in Cairo. Still, the social and economic pressures of having a crusade on your doorstep led the Mamluks to overthrow their Ayyubid masters. The Mamluks eventually conquered all the crusader states in Syria, and the rest of the Ayyubids in Syria too. The Mamluk dynasties in Egypt lasted for almost another 300 years until they were conquered by the Ottomans. Would any of that have happened without the crusades?

Speaking of the Ottomans, the crusades were certainly beneficial for them too. Initially they were just another small Turkic state in Anatolia, and they rose to power for various reasons that might not have anything to do with the crusades directly, but they were able to conquer Constantinople and the remnants of the Byzantine Empire in 1453. Constantinople had already been conquered once before, by the Fourth Crusade in 1204. The Byzantines recovered the city in 1261, but the empire never really recovered. Could they have survived the Ottomans, if the empire hadn’t been shattered by crusaders first?

The Maronites of Lebanon joined with the Latin Catholic Church due to the presence of Latin crusaders, and they’re still Latin Catholics today. The arrival of the crusaders also allowed the Armenians to form their own state in southern Anatolia (the Kingdom of Cilician Armenia). The Kingdom of Georgia further north in the Caucasus was also inspired to fight against their Seljuk rulers once the crusaders arrived.

Far to the south, the Christian kingdoms in Nubia and Ethiopia were also indirectly affected by the crusades. The Nubians fought alongside the exiled Fatimids after the Ayyubids took over Egypt - and of course, as mentioned, the Ayyubid takeover was a result of failed crusader invasion. Later in the 15th century, Ethiopian delegates participated in a church council in Florence, thanks to the renewed ties between Ethiopia and Europe in the aftermath of the crusades.

These are just a few examples that came to mind (based on previous questions that have been asked here on AH recently). I’m sure we could list many more examples. The economic impact from trade was far more significant than any political repercussions, for instance. But would all of these impacts happen anyway, even if there were no crusades? Do these count as “lasting changes” even if the crusader states themselves didn’t last?

Unfortunately, it’s very hard to say why something didn’t happen, but hopefully these examples show that things did change, even if they weren’t the kind of changes the crusaders hoped for.