Hmmm, I'll snag this article from one I wrote elsewhere. A little cheating gets one far in life... 
On an important event in Eastern European history:
Julián could hardly believe his eyes, or rather his ears.
Here he was, hundreds of miles away from home, and yet once again he was surrounded by people who spoke his language and used his customs; he was among his own kind again. The myths had turned out to be true after all.
King Béla IV of Hungary had dispatched Julián, a Dominican friar, eastward to see if the myths about the Volga Hungarians were true. In the late 9th century the Magyars lived near the Volga in a tribal empire that was collapsing, and when two neighboring tribes the Bulgars and Pechenegs attacked the Magyar homeland (Etelköz, Between the Rivers) the Magyars fled westward. They had for some time been doing mercenary work for the Slavic prince Svatopluk in Europe and his Moravian Empire (located in modern eastern Czech Republic), and they knew the passes through the Carpathians and more importantly the abundant grasslands beyond very well. The Magyars broke into the Carpathian Basin in 896-899 and seized the southern half of Svatopluks empire, old Roman Pannonia, and after some adventures across Europe settled down to establish the Hungarian kingdom. However, not all the Magyar tribes had managed to flee Etelköz, and for centuries afterwards rumors had persisted that they had somehow survived in the Volga region. These rumors prompted Béla IV to dispatch Julián and two others to explore the eastern lands and seek out these survivors, should they still indeed exist. It was 1236, and after a long journey through Cumania and the southern Russian lands, Julián was now standing in Bashkiria in the Volga Bulgar khanate, and he had indeed found the left-behind Magyars.
Elated, Julián made his way back to his king in Hungary (his two companions not having survived the journey) and reported his magnificent find. Equally elated, Béla IV dispatched Julián once more to Bashkiria to persuade the Bashkir Magyars to move to the kingdom of Hungary, to finally unite the whole Magyar nation in its new Carpathian home. Julián immediately left for Bashkiria but when he reached the Russian city of Suzdal in 1237 he met a few straggling members of the lost Magyar tribe, and they implored Julián to turn back and flee for his life. In the intervening time since his last visit a great power had arisen out of the east and invaded Bashkiria, slaughtering and scattering nations. The Volga Magyars were no more, Julián was told, and he had best return and warn his sovereign of the coming storm.
Julián did as advised, and immediately reported back to his king that hed better make preparations, because the Mongols were coming.
**********************************************
In 1219 Genghis Khan, who had united several disparate Steppe tribes in Mongolia to create a powerful nomadic empire, turned his attention away from northern China which he had just conquered and sent a force to invade the Islamic Khwarizmian empire. Soon the Mongols were on the Black Sea, and Genghis sent two trusted generals, Jebe and Subedei, with a force of 20,000 northwards into the Caucasus, where they easily pushed aside the Georgians, Circassians and Alans. On 16. June 1223, the Mongols defeated a combined Cumanian-Russian force at the River Kalka, but despite this stunning victory the Mongols withdrew. They came back a few years later, however, dispatched by Genghis Khans successor Ogedei, determined to spread the Mongol domains westward. In 1229 this army defeated the Cumanians again at the River Yaik, though the Cumanian Khan Köten was later able to defeat them near the Black Sea, temporarily halting the Mongol advance. Ogedei sent one of Genghis Khans grandsons, Batu, with a massive army to claim the western lands and it was this army in 1237 that laid waste to Bashkiria and scattered the Volga Magyars, among many others. In 1238 the Cumans were forced westward by the Mongols, and they cut a deal with the Hungarian king Béla IV that allowed them to settle within his kingdom (1239). Béla IV hoped to use the famous Cumanian light cavalry in his defenses but events would conspire against this. Soon Ryazan, Moscow, Vladimir, Suzdal and Yaroslavl were burning as the Mongols laid waste to Russia.
In December 1240, as the Mongol forces were reducing the Rus capital Kiev to ashes, a Mongol emissary arrived in Béla IVs court demanding that Hungary bow down before the Khan and acknowledge Mongol suzerainty. Béla IV refused, claiming that a Christian prince could never acknowledge a pagan rulers overlordship. Within three weeks after the destruction of Kiev Mongol forces were on Rus western border, poised to strike into Europe.
The Mongol plan was amazing in its audacity, and also showed the Mongols did not blunder blindly into their conquests but relied on an intricate system of intelligence and scouting , anticipating all resistance and terrain their armies might encounter ahead. They split their army into three, with Hungary as their main objective but a northern force led by the Mongol princes Baidar and Kaidu to preclude Polands intervention to save Hungary (the Mongols being aware of traditional Polish-Hungarian friendship) and a southern force led by Ogedeis son Kadan dispatched to the Balkans to ensure the Bulgars and Byzantines would not intervene. Batu and Subedei themselves led the force that invaded Hungary.
In early February 1241, the Mongols launched their invasion of Poland with a mere 20,000 and very quickly were able to destroy the eastern cities of Lublin and Sandomierz. Poland since 1138 had been leaderless, as the then dying king had divided the country between his sons (a la Charlemagne) and the country had for the past century been disunited and without any central authority. Local princes, all of the former ruling dynasty (Piast), were too absorbed in their own concerns to be able to organize an effective resistance to the Mongols. On 03. March the Mongols defeated a Polish force led by Krakóws Prince Boleslaw V when he foolishly led his forces out of the citys protective walls, and devastated Kraków. They moved on and destroyed Chmielnik (24. March) but were held up at Wroclaw (27. March: German Breslau), which they then by-passed. There was only one significant military force left in Poland, and this was the Silesian Prince Henryk II Poboznys (The Pious) army at Legnica (German: Leignitz).
Henryk II was desperately waiting for re-inforcements to arrive from his brother-in-law, Vladislav I, king of Bohemia. Henryk II had no idea where his brother-in-law was, but the Mongols did only two marching days away which is why they lifted their siege of Wroclaw and advanced towards Henryk II, to destroy his force before help arrived. Henryk had cobbled together a force of 30,000 composed of Polish knights, cavalry, Moravian and German infantry, Teutonic Knights and French Knights Templar. On 09. April, 1241, fearing the consequences of the Mongol armies being re-inforced, Henryk II decided not to wait for his brother-in-law and led his forces out of the safety of Legnica to meet the Mongols. Henryk IIs army led several ferocious frontal assaults against the Mongols on a field near Legnica, with the first several ending in disaster for the Europeans but the final one, led by Mieszko of Opole, broke the Mongol lines and the Mongols began to flee the battle in disarray.
Or, at least, thats what Henryk IIs forces thought. When they saw the Mongols withdrawing they charged headlong in pursuit. Unfortunately they were victims of an old Steppe tactic of feigned retreat, and as the knights foolishly charged forward without the protection of their infantry support, they fell easy victims to several Mongol ambushes. After cutting down all of the knights, the Mongols turned on the infantry and slaughtered them en masse. Henryk II himself was caught trying to flee the battlefield, and the Mongols paraded his severed head on a pike around Legnica. The last bastion of Polish resistance had fallen.
The Mongol forces then left Poland and continued southward into Moravia, which they laid waste to. Vladislav I, hearing of the disaster at Legnica, withdrew to Bohemia and waited. Only the mighty Moravian fortress of Olomouc (German: Olmütz) was able to resist the Mongols. Despite their widespread devastation of Moravia, Baidar and Kaidu were less interested in the Czechs than in keeping them from interfering with the Mongols Hungarian operations, currently underway. Succeeding in this, Baidar and Kaidu marched southwards into Hungary, where they rejoined the main Mongol forces under Batu and Subedei.
**********************************************
Kadan and Subedei, in the meanwhile, led an invasion of the Romanian principalities of Moldavia and Wallachia, wreaking utter devastation among the Romanians before entering Hungarian Transylvania in March 1241. The main Mongol force under Batu had seized the Hungarian/Rusyn border city of Halycz (Ukrainian: Galich) and forced the passes through the Carpathians.
At this point disaster struck the Hungarian forces, not from without but from within. With the advance of the Mongols towards Buda suspicion among the aristocracy fell on the Cumanians, and Béla IV had to move their khan, Köten, and his family to the protection of one of the royal palaces of Pest but a mob managed to gain entrance to the castle and murder the khan, tossing his head onto the stones of the street. There is great speculation still today that the mob was instigated by Friedrich Babenberg of Austria, who was in Buda to ostensibly help Béla IV against the Mongols but in reality was scheming to seize western provinces from Hungary. The Cumanian clans held a council and decided at this critical moment when their cavalry were most needed by Béla IV to de-camp and abandon Hungary for Bulgaria. Hungarys most valuable allies had just abandoned it.
Béla IV set off from Buda with approximately 60,000 troops towards the Mongols who retreated from Béla IV until they reached the Sajó River, near Muhi. On 10. April, the Hungarians crossed the only stone bridge across the river and set up camp. Throughout that night however the Mongols built a wooden bridge across the river and surrounded the Hungarians. The Hungarian forces outnumbered the Mongols so they did not attack directly, instead using a brilliant ruse to force the Hungarians into an unfavorable battle. The Mongols left a gap in their lines that some Hungarians discovered and slowly they began to withdraw secretly through the Mongol gap. Unnknown to the Hungarians, the Mongols were perfectly aware of the Hungarian movements and at a point when the Hungarian forces were strung out and trying to maintain an organized withdrawal, the Mongols struck. The resulting battle was a near massacre of the Hungarian forces. Béla IV himself and a handful of knights managed by skin of teeth to escape the battle and flee westwards, where Friedrich Babenberg had them imprisoned in Austria until they paid a ransom and handed over the provinces he desired.
The Mongol forces fanned out across Hungary destroying everything in their path; the countrys population was said to have been reduced by 50% between 1241-42, with the regions of the Great Plains losing some 80% of their population. Batu at one point moved menacingly towards Vienna, reaching Neustadt in July, though he proceeded no further. Kadan chased after Béla IV to the Dalmatian coast, where the king fled first to the unprotected island of Rab in the Adriatic, then to the island fortress of Trogir (Trau, near modern Split) at which he kept a ship ready to ferry him to Italy should the Mongols approach the island. The Mongol forces raged down the Dalmatian coast but the mountainous terrain and lack of grasslands for the horses impaired their effectiveness. At Grobnicko Polje (near modern Rijeka, Croatia) Kadans forces met their first defeat in Europe, handed to them by Croat forces. Kadan by-passed the old Roman fortress at Split and wandered aimlessly into northern Albania. The Mongols never did manage to capture Béla IV.
Then, out of the blue, they simply left in March 1242. A messenger had arrived from Mongolia informing Batu that the great Khan Ogedei had died, and that Batu should report immediately back to Karakorum for the traditional quriltai to decide the next Mongol Khan. Europe did not know this and simply watched stunned as the Mongol forces withdrew. Of course, Hungarys gain was Russias loss; Batu withdrew to the city of Sarai on the Volga and established his own khanate, which would rule over the Russian lands (under the name eventually of the Golden Horde) for 238 years until Ivan III would renounce Tartar rule in Russia in 1480, after successfully staring down a Tartar army at the River Ugra.
Part II a' comin':

On an important event in Eastern European history:
Julián could hardly believe his eyes, or rather his ears.
Here he was, hundreds of miles away from home, and yet once again he was surrounded by people who spoke his language and used his customs; he was among his own kind again. The myths had turned out to be true after all.
King Béla IV of Hungary had dispatched Julián, a Dominican friar, eastward to see if the myths about the Volga Hungarians were true. In the late 9th century the Magyars lived near the Volga in a tribal empire that was collapsing, and when two neighboring tribes the Bulgars and Pechenegs attacked the Magyar homeland (Etelköz, Between the Rivers) the Magyars fled westward. They had for some time been doing mercenary work for the Slavic prince Svatopluk in Europe and his Moravian Empire (located in modern eastern Czech Republic), and they knew the passes through the Carpathians and more importantly the abundant grasslands beyond very well. The Magyars broke into the Carpathian Basin in 896-899 and seized the southern half of Svatopluks empire, old Roman Pannonia, and after some adventures across Europe settled down to establish the Hungarian kingdom. However, not all the Magyar tribes had managed to flee Etelköz, and for centuries afterwards rumors had persisted that they had somehow survived in the Volga region. These rumors prompted Béla IV to dispatch Julián and two others to explore the eastern lands and seek out these survivors, should they still indeed exist. It was 1236, and after a long journey through Cumania and the southern Russian lands, Julián was now standing in Bashkiria in the Volga Bulgar khanate, and he had indeed found the left-behind Magyars.
Elated, Julián made his way back to his king in Hungary (his two companions not having survived the journey) and reported his magnificent find. Equally elated, Béla IV dispatched Julián once more to Bashkiria to persuade the Bashkir Magyars to move to the kingdom of Hungary, to finally unite the whole Magyar nation in its new Carpathian home. Julián immediately left for Bashkiria but when he reached the Russian city of Suzdal in 1237 he met a few straggling members of the lost Magyar tribe, and they implored Julián to turn back and flee for his life. In the intervening time since his last visit a great power had arisen out of the east and invaded Bashkiria, slaughtering and scattering nations. The Volga Magyars were no more, Julián was told, and he had best return and warn his sovereign of the coming storm.
Julián did as advised, and immediately reported back to his king that hed better make preparations, because the Mongols were coming.
**********************************************
In 1219 Genghis Khan, who had united several disparate Steppe tribes in Mongolia to create a powerful nomadic empire, turned his attention away from northern China which he had just conquered and sent a force to invade the Islamic Khwarizmian empire. Soon the Mongols were on the Black Sea, and Genghis sent two trusted generals, Jebe and Subedei, with a force of 20,000 northwards into the Caucasus, where they easily pushed aside the Georgians, Circassians and Alans. On 16. June 1223, the Mongols defeated a combined Cumanian-Russian force at the River Kalka, but despite this stunning victory the Mongols withdrew. They came back a few years later, however, dispatched by Genghis Khans successor Ogedei, determined to spread the Mongol domains westward. In 1229 this army defeated the Cumanians again at the River Yaik, though the Cumanian Khan Köten was later able to defeat them near the Black Sea, temporarily halting the Mongol advance. Ogedei sent one of Genghis Khans grandsons, Batu, with a massive army to claim the western lands and it was this army in 1237 that laid waste to Bashkiria and scattered the Volga Magyars, among many others. In 1238 the Cumans were forced westward by the Mongols, and they cut a deal with the Hungarian king Béla IV that allowed them to settle within his kingdom (1239). Béla IV hoped to use the famous Cumanian light cavalry in his defenses but events would conspire against this. Soon Ryazan, Moscow, Vladimir, Suzdal and Yaroslavl were burning as the Mongols laid waste to Russia.
In December 1240, as the Mongol forces were reducing the Rus capital Kiev to ashes, a Mongol emissary arrived in Béla IVs court demanding that Hungary bow down before the Khan and acknowledge Mongol suzerainty. Béla IV refused, claiming that a Christian prince could never acknowledge a pagan rulers overlordship. Within three weeks after the destruction of Kiev Mongol forces were on Rus western border, poised to strike into Europe.
The Mongol plan was amazing in its audacity, and also showed the Mongols did not blunder blindly into their conquests but relied on an intricate system of intelligence and scouting , anticipating all resistance and terrain their armies might encounter ahead. They split their army into three, with Hungary as their main objective but a northern force led by the Mongol princes Baidar and Kaidu to preclude Polands intervention to save Hungary (the Mongols being aware of traditional Polish-Hungarian friendship) and a southern force led by Ogedeis son Kadan dispatched to the Balkans to ensure the Bulgars and Byzantines would not intervene. Batu and Subedei themselves led the force that invaded Hungary.
In early February 1241, the Mongols launched their invasion of Poland with a mere 20,000 and very quickly were able to destroy the eastern cities of Lublin and Sandomierz. Poland since 1138 had been leaderless, as the then dying king had divided the country between his sons (a la Charlemagne) and the country had for the past century been disunited and without any central authority. Local princes, all of the former ruling dynasty (Piast), were too absorbed in their own concerns to be able to organize an effective resistance to the Mongols. On 03. March the Mongols defeated a Polish force led by Krakóws Prince Boleslaw V when he foolishly led his forces out of the citys protective walls, and devastated Kraków. They moved on and destroyed Chmielnik (24. March) but were held up at Wroclaw (27. March: German Breslau), which they then by-passed. There was only one significant military force left in Poland, and this was the Silesian Prince Henryk II Poboznys (The Pious) army at Legnica (German: Leignitz).
Henryk II was desperately waiting for re-inforcements to arrive from his brother-in-law, Vladislav I, king of Bohemia. Henryk II had no idea where his brother-in-law was, but the Mongols did only two marching days away which is why they lifted their siege of Wroclaw and advanced towards Henryk II, to destroy his force before help arrived. Henryk had cobbled together a force of 30,000 composed of Polish knights, cavalry, Moravian and German infantry, Teutonic Knights and French Knights Templar. On 09. April, 1241, fearing the consequences of the Mongol armies being re-inforced, Henryk II decided not to wait for his brother-in-law and led his forces out of the safety of Legnica to meet the Mongols. Henryk IIs army led several ferocious frontal assaults against the Mongols on a field near Legnica, with the first several ending in disaster for the Europeans but the final one, led by Mieszko of Opole, broke the Mongol lines and the Mongols began to flee the battle in disarray.
Or, at least, thats what Henryk IIs forces thought. When they saw the Mongols withdrawing they charged headlong in pursuit. Unfortunately they were victims of an old Steppe tactic of feigned retreat, and as the knights foolishly charged forward without the protection of their infantry support, they fell easy victims to several Mongol ambushes. After cutting down all of the knights, the Mongols turned on the infantry and slaughtered them en masse. Henryk II himself was caught trying to flee the battlefield, and the Mongols paraded his severed head on a pike around Legnica. The last bastion of Polish resistance had fallen.
The Mongol forces then left Poland and continued southward into Moravia, which they laid waste to. Vladislav I, hearing of the disaster at Legnica, withdrew to Bohemia and waited. Only the mighty Moravian fortress of Olomouc (German: Olmütz) was able to resist the Mongols. Despite their widespread devastation of Moravia, Baidar and Kaidu were less interested in the Czechs than in keeping them from interfering with the Mongols Hungarian operations, currently underway. Succeeding in this, Baidar and Kaidu marched southwards into Hungary, where they rejoined the main Mongol forces under Batu and Subedei.
**********************************************
Kadan and Subedei, in the meanwhile, led an invasion of the Romanian principalities of Moldavia and Wallachia, wreaking utter devastation among the Romanians before entering Hungarian Transylvania in March 1241. The main Mongol force under Batu had seized the Hungarian/Rusyn border city of Halycz (Ukrainian: Galich) and forced the passes through the Carpathians.
At this point disaster struck the Hungarian forces, not from without but from within. With the advance of the Mongols towards Buda suspicion among the aristocracy fell on the Cumanians, and Béla IV had to move their khan, Köten, and his family to the protection of one of the royal palaces of Pest but a mob managed to gain entrance to the castle and murder the khan, tossing his head onto the stones of the street. There is great speculation still today that the mob was instigated by Friedrich Babenberg of Austria, who was in Buda to ostensibly help Béla IV against the Mongols but in reality was scheming to seize western provinces from Hungary. The Cumanian clans held a council and decided at this critical moment when their cavalry were most needed by Béla IV to de-camp and abandon Hungary for Bulgaria. Hungarys most valuable allies had just abandoned it.
Béla IV set off from Buda with approximately 60,000 troops towards the Mongols who retreated from Béla IV until they reached the Sajó River, near Muhi. On 10. April, the Hungarians crossed the only stone bridge across the river and set up camp. Throughout that night however the Mongols built a wooden bridge across the river and surrounded the Hungarians. The Hungarian forces outnumbered the Mongols so they did not attack directly, instead using a brilliant ruse to force the Hungarians into an unfavorable battle. The Mongols left a gap in their lines that some Hungarians discovered and slowly they began to withdraw secretly through the Mongol gap. Unnknown to the Hungarians, the Mongols were perfectly aware of the Hungarian movements and at a point when the Hungarian forces were strung out and trying to maintain an organized withdrawal, the Mongols struck. The resulting battle was a near massacre of the Hungarian forces. Béla IV himself and a handful of knights managed by skin of teeth to escape the battle and flee westwards, where Friedrich Babenberg had them imprisoned in Austria until they paid a ransom and handed over the provinces he desired.
The Mongol forces fanned out across Hungary destroying everything in their path; the countrys population was said to have been reduced by 50% between 1241-42, with the regions of the Great Plains losing some 80% of their population. Batu at one point moved menacingly towards Vienna, reaching Neustadt in July, though he proceeded no further. Kadan chased after Béla IV to the Dalmatian coast, where the king fled first to the unprotected island of Rab in the Adriatic, then to the island fortress of Trogir (Trau, near modern Split) at which he kept a ship ready to ferry him to Italy should the Mongols approach the island. The Mongol forces raged down the Dalmatian coast but the mountainous terrain and lack of grasslands for the horses impaired their effectiveness. At Grobnicko Polje (near modern Rijeka, Croatia) Kadans forces met their first defeat in Europe, handed to them by Croat forces. Kadan by-passed the old Roman fortress at Split and wandered aimlessly into northern Albania. The Mongols never did manage to capture Béla IV.
Then, out of the blue, they simply left in March 1242. A messenger had arrived from Mongolia informing Batu that the great Khan Ogedei had died, and that Batu should report immediately back to Karakorum for the traditional quriltai to decide the next Mongol Khan. Europe did not know this and simply watched stunned as the Mongol forces withdrew. Of course, Hungarys gain was Russias loss; Batu withdrew to the city of Sarai on the Volga and established his own khanate, which would rule over the Russian lands (under the name eventually of the Golden Horde) for 238 years until Ivan III would renounce Tartar rule in Russia in 1480, after successfully staring down a Tartar army at the River Ugra.
Part II a' comin':