In late 377 AD, the Roman Diocese of Thracia (roughly modern-day Bulgaria) was in turmoil, still reeling from the indecisive Battle of Ad Salices against Fritigern’s Gothic Alliance, where much of the Thracian legions had been crushed or severely weakened. Following that clash, the Goths retreated to and occupied northern Thracia to lick their wounds while the patchwork remainder of the Roman legions fled south, looking over their shoulders in fear, certain that it was only a matter of time before the Goths would take to the march again, knowing there was every chance the barbarians would this time shatter the remaining imperial forces and seize all of Thracia for themselves. Messengers were despatched at haste to all corners of the empire pleading for a relief army, yet the only forces sizeable enough to tackle and repel the Gothic horde were the Praesental Armies of the Eastern and Western Emperors and they were engaged in troubles of their own: Emperor Valens and his Eastern Praesental army were pinned down on the Persian frontier while Emperor Gratian and his Western forces were engaged in troubles on the Rhine and upper Danube, and neither was likely to reach Thracia until spring 378 AD at the earliest.

So the patchwork Thracian legions were forced to look to the terrain as a means of holding back the Goths’ expected southwards advance. The Haemus (Balkan) Mountains present an almost unbroken ridge that runs east to west across that region, and it was Magister Equitum Saturninus who rallied the Roman forces and oversaw the hasty fortification of the five main passes across this range. With the passes blocked, the Goths were penned into the lands north of the mountains. Saturninus’ goal was to protect the southerly and central portion of Thracia and to starve the Goths (who had by now plundered and stripped the northern part of the Diocese bare of grain and fodder) into submission. Saturninus did this and did it well for some six to nine months, repelling numerous Gothic attacks on the mountain blockades as the Roman soldier and historian, Ammianus Marcellinus, attests:

Since everything that could serve as food throughout the lands . . . had been used up, the barbarians, driven alike by ferocity and hunger, strove with all their might to break out . . . after many attempts, they were overwhelmed by the vigour of our men, who strongly opposed them amid the rugged heights.

Had this defensive system held out until the two emperors arrived with their relief armies, then the fate of the Eastern Empire (and, consequently, the Western Empire) might have been significantly altered. But something happened in late 377 AD: the Huns – those strident riders from the Eurasian steppe who had driven the Goths into Roman lands just a year earlier – agreed some form of alliance with their erstwhile foes. It was almost certainly just a subdivision of the Huns who crossed over the River Danubius to swell the Gothic ranks, but they brought with them a different style of warfare, diversifying and intensifying the threat posed to the Romans. They also brought with them Alani riders and, at some point, the Germanic Taifali also joined the ethnically varied alliance. Fritigern, The Arian Christian Iudex (judge or leader) of this horde, had a monumental task on his hands. Organising over one hundred thousand homeless people would have been a gargantuan undertaking in itself. Added to this, power struggles with the likes of Alatheus and Saphrax – leaders of the pagan Greuthingi Goths – and cultural clashes with the northern horsemen were surely rife and frequent. But one thing kept them united: the knowledge of their now overwhelming numerical superiority . . . and the promise of rich conquest and plunder in the lands south of the mountains.

Saturninus got wind of the alliance between the Goths and the Huns and realized with horror what this meant: the passes simply could not bear the weight of the Goths’ new-found forces. His choices were equally poisonous: to stay, fight and surely perish with all his forces or to flee, cede the passes and preserve his meagre regiments? Either way, the fate of all Thracia and its hundreds of thousands of imperial subjects must have looked truly black.

Legionary: The Scourge of Thracia tells the story of five legionaries who are cast into this brewing storm . . .