Battle of Sirmium (488)

The Battle of Sirmium (Battle of the Ulca) occurred in 488 between the Gepids under Thraustila and the Ostrogoths under Theodoric the Great. While on his way to invading Italy in terms of Emperor Zeno, he and his forces passed nearby the Gepid capital of Sirmium. King Thraustila of the Gepids saw this moment as an opportunity to halt the Ostrogothic invasion and possibly to take revenge over their rivalry during the 460s and 470s. The Gepids marched westwards and encountered Theodoric at the Ulca River, where the battle was said to be situated. The Gepids were defeated in the incursion and Thraustila was possibly killed, as he is not mentioned again. Theodoric the Great in 489 crossed the Julian Alps where after a 4 year campaign he successfully conquered Italy. In 504, Theodoric and Thraustila’s son Thrasaric would begin another war between each other that in which the Ostrogoths triumphed and forced the Gepids out of Sirmium.

Background
After the death of King Attila, the Hunnic Empire was in a Civil War as the western half quickly fragmented due to a revolt of Germanic tribes under Ardaric. His alliance defeated and killed King Ellac at the Battle of Nedao in 454, fragmenting Hunnic rule and freeing both the Gepids and Ostrogoths from subjugation. The Gepids had settled in Gepidia, which is now Transylvania. However, the Ostrogoths fought a coalition involving Gepids and many others, but defeated their combined forces at the Battle of Bolia in 469. However, the Ostrogoths were forced to migrate out of their holdings in Pannonia, including Sirmium. The Gepids eventually absorbed the city into their domain in 473.

The Battle
Over the course of the 480’s, Theodoric the Great launched several campaigns against Emperor Zeno. In 488 to force him out of the Eastern Roman Empire, he gave him the objective of overthrowing Odoacer and proclaiming himself the new king of Italy. He agreed to his terms and in the fall of 488 left from the fortress of Sistova in Thracia (Svishtov, Bulgaria) on his way to Italy, following the Roman roads along the Danube. The Ostrogothic population of 200,000 followed in wagons, as they were keen on searching for a definitive home without constant conflict and was overall a better location to settle.

With little effort, Theodoric marched 300 miles, while hugging the Danube and passed nearby Sirmium, the residence of Gepid King Thraustila. The Gepids ever since 473 had held the cities of Singidunum (Belgrade) and Sirmium as their own. The Great Danubian Highway traversed through these settlements, which posed a challenge as it would be the most viable way for Theodoric to continue west to reach Italy. King Thraustila ordered an embassy to confront him while in between the Drave and Save Rivers. Theodoric promised only to pass through Gepid territory and that he wouldn’t use any of the resources and land present in the region. His response did not please the Gepid King, as he would allow Theodoric to pass if he were able to defeat his Gepids in battle. The two armies supposedly encountered each other at the "Ulca River", which its modern

correspondence is unknown. The location of the battle is thought to have most likely taken place between the current Croat cities of Vinkovci and Vukovar.

The territories surrounding the Danube suffered from terrible weather during the late autumn, switching between a state of cool wet marshland and frigid icy grasslands. Under the orders of Thraustila, he ordered his men to block the passageway across the Ulca River, attempting to starve out and weaken the Ostrogoths. The Ulca's muddy climate would've made fording the river ambitious and made any army to do so highly vulnerable. Theodoric marched his people through freezing temperatures and steep roads ending in several thousands dying of starvation. After hours of pondering, he found a more suitable fording location where he ordered his men to cross with strength and agility. Many of the crossing soldiers were engulfed in mud, making them easy targets for Gepid archers. Other men that succeeded in the crossing collided with the Gepid forces waiting on the other side.

Seeing the situation dire, he spoke to his soldiers along the lines of, "Who decides to face the enemy head on should follow me. I am truly your greatest leader, for you should only charge under my command. Those Gepids shall feel my presence and know my strength. I will be your savior and keep our nation thriving onwards." He charged his remaining forces into battle well on horseback, demolishing and crumbling all of the Gepid infantry. It is very likely that King Thraustila himself was killed in battle, as he is never mentioned again. The battle was a Gepid bloodbath, as the majority who survived were only saved by the arrival of night. A great capacity of supply wagons (filled mostly of corn) were also robbed from the Gepids. The Gepids were absolutely demolished and would come under the rule of the king's son Thrasaric, and proved to be ambitious on avenging his father's death.

Aftermath
The battle which left the Gepid army in catastrophe, allowed Theodoric the Great to pillage and campaign throughout the Gepid Kingdom with very little resistance, throughout the winter and spring of 489. Theodoric left Gepidia around July and crossed the Julian Alps in August where he faced Odoacer at the battle of the Isontius. After a four year war, Theodoric would prove victorious and be crowned as King of Italy, which he would rule until his death in 526. The Gepids were humiliated and torn apart by the battle and following campaign by the Ostrogoths. After a decade of recovery, the Gepid King Thrasaric, son of Thraustila vowed vengeance over what Thedoric had done to his kingdom. After the reconquest of Sirmium, another war began between the Gepids and Ostrogoths between 504 and 505.

Location
The exact location of the Battle of Sirmium is unknown, due to the Ulca River being unidentifiable in correspondence to the modern world. The battlegrounds are also mentioned to have been nearby the city of Cibalis, whose location is also unknown. It is thought that the battle may have been at the same location of the Battle of Cibalae in 314, between Constantine the Great and Licinius, which took place in Vinkovci. If the battle was near or in Vinkovci, that would make the Ulca River compatible with the Bosut River, which also corresponds to where the battle took place. It is most likely that they are the same river and that the Bosut is the river described in the battle.

Ancient Sources
Ennodius

Modern Sources
https://en.wikipedia.org/

https://books.google.com/books?id=dM3kdRzztiIC&source=gbs_navlinks_s

https://books.google.com/books?id=LXgfAAAAMAAJ&source=gbs_navlinks_s

https://www.google.com/books/edition/Anastasius_I/BmcbAAAAYAAJ?hl=en&gbpv=0

https://books.google.com/books?id=hwxSAQAAMAAJ&dq=hiulca+palus&source=gbs_navlinks_s