When you’re talking about the “Battle of Kosovo” it’s important to be specific. As far as I know, there have been at least five “Battles of Kosovo” fought over the years, and that’s not including the Kosovo Operation in World War II and the 1998-1999 Kosovo War. Of those five battles, the Ottomans were major belligerents in three and contributed troops to a fourth.
When most people talk about “the Battle of Kosovo,” they’re talking about the 1389 Battle of Kosovo, in which two otherwise feuding Serbian principalities, along with the Kingdom of Bosnia, fought an Ottoman army under Sultan Murad I. That battle was a tactical draw but a strategic Ottoman victory (both armies were decimated, but the Ottomans could afford the loss while the Serbians couldn’t) that cost the lives of both commanders (Murad and the Serbian Prince Lazar) and led to the early Ottoman domination of the Balkans. Despite the fact that it should be considered an Ottoman victory, the fight put up by the outnumbered Serbian army in 1389 became so important to Serbian national identity that Kosovo itself was seen as its birthplace. The Serbs brutally resisted Kosovo’s independence movement in the 1990s not just because it was a secessionist movement and countries generally resist those, but also because it struck at the heart of Serbian identity.
However, as the chilly temperature outside makes it clear that it’s not June, we’re not going to talk about that Battle of Kosovo today. Instead we’re talking about the Second Battle of Kosovo, which helped to re-establish Ottoman control over the Balkans and also highlights the Ottoman army’s ability to learn from its enemies, in this case the Hungarian army. Yes, that’s right. One of the things you don’t always learn in history class (at least I never did) is that Hungary was a serious military power back in the day.
This is going to be a long walk to a short battle, but I think you’ll enjoy some extra background details.
Between the two battles of Kosovo, the Ottoman Empire suffered a massive setback. In 1402, Sultan Bayezid I decided that, with his European frontier pretty secure (despite his failure to conquer Constantinople), he could safely turn his attention to eliminating Timur, who was threatening Ottoman authority in eastern and central Anatolia. This proved to be a very bad idea. After Timur’s overwhelming victory at the Battle of Ankara (Bayezid was captured and died in 1403, still Timur’s prisoner), the Ottomans lost most of their Anatolian territory and spent about a decade embroiled in a civil war between Bayezid’s sons that also meant the loss of most of their European territories. The civil war finally ended with the accession of Mehmed I as undisputed Sultan in 1413, but he spent as much time stabilizing the empire as trying to regain its former territory. Most of the work of rebuilding the empire would fall to Mehmed’s successor, Murad II (d. 1451), who became Sultan when Mehmed died in 1421.
Murad spent the 1430s reconquering parts of the Balkans. But when he annexed most of Serbia (in 1439), he ran into the Kingdom of Hungary, which was emerging as a powerful military force in its own right. Much of this was due to the work of a Romanian-Hungarian noble named John Hunyadi (d. 1456), who developed his military skills serving in Italian and German armies before being named governor (voivode, which literally means “warlord”) of Transylvania, and later regent of Hungary on behalf of the very young King Ladislaus V. In both capacities he assumed responsibility for Hungary’s southern defenses.
Hunyadi studied the wars between the Czech Hussites (the original Protestants, whose movement predates the Protestant Reformation by more than a century) and the Catholics (chiefly Hungary and the Holy Roman Empire) in the 1420s and 1430s. The Hussites utilized a laager, which was a quick fortification assembled using wagons that could be set up in the middle of a battlefield in order to protect infantry from cavalry, to great effect. They didn’t invent this very old tactic, but they substantially improved it by adding howitzers and firearms to the makeshift fort.
Hunyadi figured that the laager could be used against the very dangerous Ottoman cavalry, and so he did. During the so-called “Long Campaign” in 1443-1444, the Hungarian army under Hunyadi’s command inflicted a number of significant defeats on the Ottomans, frequently relying on the laager (or as it’s called in German, the wagenburg or “wagon castle”) to pound the Ottoman cavalry with artillery while the Hungarian soldiers were safe behind its fortifications (the Ottomans hadn’t yet really embraced field guns at this point). Hunyadi was so successful that Murad was forced (well, sort of–he also seems to have been genuinely tired of fighting) to sign a 10 year peace treaty with the Hungarians in August 1444.
That treaty lasted all of three months. After its conclusion (and the conclusion of another treaty with the Ottomans’ chief Anatolian rival, the Karamanids), Murad made the shocking decision to abdicate and pass the empire to his son, the 12 year old Mehmed II (who would one day be known as “Mehmed the Conqueror,” but we’re definitely not there yet). Let me stress that Murad wasn’t forced to abdicate. Whether because he was tired of fighting/governing or wanted to ensure a smooth succession to Mehmed (or both), he gave up the throne of his own volition.
For the Christians, Murad’s retirement created both a risk (that the young new sultan might scrap the treaty in order to show his mettle to his skeptical army) and an opportunity (in that the Ottomans were suddenly being led by a child and might be really vulnerable to a serious offensive). So, a whole bunch of Christian kingdoms (so many that it’s sometimes referred to as a Crusade)–including Poland, Hungary, the Holy Roman Empire, Prussia, Croatia, Bohemia, Lithuania, and what was left of Serbia–got together and, led by Hunyadi and King Władysław III of Poland, decided to scrap the treaty themselves and attack the Ottomans.
Unfortunately for the Christians, Mehmed recognized that he wasn’t ready for this kind of major war (more importantly, his army recognized that he wasn’t ready for it), and so he called his father out of retirement to assume command of the Ottoman army. This led to the Battle of Varna, in 1444, which might well have been won by the Christians if Hunyadi and Władysław had listened to their own advisers and relied on the laager to carry the day. They opted instead to attack the Ottoman line, and then Władysław went further and decided to lead a cavalry charge, without support, that got him killed and his Polish knights routed. Varna was a decisive Ottoman victory that smashed the “Crusade,” such as it was, to pieces. Unfortunately for Murad, who really hadn’t wanted to resume command of the army, he was forced to resume ruling the whole empire in 1446, when a potential Janissary revolt (possibly engineered by Grand Vizier Çandarlı Halil Paşa) threatened to violently unseat Mehmed.
The 1448 Battle of Kosovo was Varna’s rematch. Hunyadi raised another army, though this time without all of his former Crusading allies. He did have some additional forces from nearby Wallachia, the home of the legendary Vlad Dracula (who at this point was not long removed from having been a hostage at the Ottoman court and was still the sultan’s vassal). Wallachia was ruled at that time by Hunyadi’s (then-)pal Vladislav II (d. 1456). Together those forces crossed the Danube into Serbia in September 1448. Hunyadi’s first order of business was dealing with Đurađ Branković (d. 1456, which was apparently a big year for royal deaths in eastern Europe), who ruled the Despotate of Serbia (the successor to the kingdom that had been destroyed in 1389).
The despots who ruled what was left of Serbia between 1389 and 1459 (when the Ottomans fully absorbed it) tried to chart a middle course between the Hungarians and the Ottomans, so Branković wasn’t thrilled to see Hunyadi’s army show up on his territory. Hunyadi wanted his allegiance, and in fact his war plan relied on it, but Branković demanded at a minimum the return of some Serbian territory that had been given to Hungary in that 1444 peace deal. When Hunyadi refused his terms, Branković told him to go pound sand, so Hunyadi ordered his army to pillage its way across Serbian territory in revenge.
Realizing that his army was no match for the larger Hungarian force, Branković never tried to engage Hunyadi in battle, but he made sure to provide Murad with detailed intelligence on Hungarian movements. He also appears to have done everything he could to block the march of an Albanian army, under the warlord Skanderbeg, across his territory–Skanderbeg’s forces were supposed to link up with Hunyadi’s, but never arrived. Branković suggested that Murad might want to let Hunyadi get well into Serbian territory, where it would be easier to cut the Hungarians off from their supply lines, before attacking, and Murad followed that advice. The Ottoman army, perhaps 60,000 strong, met the Hungarian army, which was 20,000-30,000 strong at most (probably closer to 20,000), at Kosovo Field (the same site as the 1389 battle) on October 17, 1448. Imagine the Hungarians’ surprise when they found the Ottomans using a new wrinkle: a laager, manned by Janissaries armed with firearms and field artillery. Murad had copied the tactic from the Hungarians, and it was to become a staple of Ottoman warfare for some time to come.
Despite being outnumbered and even though the Ottoman use of the laager negated Hungary’s most effective tactic, the battle still almost went Hunyadi’s way. A flanking assault on the Ottomans on October 18 was turned back by Ottoman cavalry, but a frontal attack actually broke through the Janissary lines and was only stopped when it got to the Ottoman camp and ran into its fortifications. At that point, an Ottoman counterattack pushed the Hungarians back and nearly routed them. Another Ottoman attack on the 19th finished the job and drove the remaining Hungarian forces from the field.
Hunyadi managed to get off the battlefield alive but was then snatched up by Branković. He’d kind of, ah, vowed to murder Branković after the latter refused to join his army, and I guess the Serbian despot didn’t take that vow in the good humor with which I’m sure it was made. After threatening to hand Hunyadi over to the Ottomans, Branković released him in exchange for a hefty ransom and the return of those territories he’d wanted in the first place. Hunyadi would bounce back, though, and he continued to defend Hungary from Ottoman aggression, even breaking Mehmed II’s siege of Belgrade in 1456 (he died shortly afterward). Murad turned his attention east and defeated both the Timurids and the Karamanids, reestablishing Ottoman control over most of Anatolia. When Murad died in 1451, Mehmed II resumed the throne. Needless to say, things went better for him the second time around.