Rome’s crisis deepens during Valerian's reign as barbarian and Persian invaders continually ravage the empire, simultaneously weakened by a persistent plague.

The empire’s hold on Dacia has remained precarious.

In the early second century, Emperor Hadrian, conscious of the difficulty of retaining the province, reportedly had contemplated its abandonment and was only deterred by consideration for the safety of the numerous Roman settlers.

In 256, Dacian tribes such as the Carpi, or Carpians, allied with the Goths, cross the Carpathians and drive the Romans from Dacia, with the exception of a few fortified places between the Timis and the Danube.

No details of the event are recorded, and the chief argument in support of the statement, found in Avienus' works, that "under the Emperor Gallienus Dacia was lost" is the sudden cessation of Roman inscriptions and coins in the country after this period.

Claudius, having earned the title Gothicus by repelling the Goths' invasion of the Balkans in 269, meanwhile campaigns successfully against the Goths in the east.

Allied to the Goths are the Gepids, a Germanic tribe that had lived on the southern Baltic coast in the first century CE, having migrated there from southern Sweden some years earlier, and again migrated southward during the second century.

The emperor gives captives the choice of settlement in the Danubian provinces or service in the Roman army.

With so many people in such a small area, a famine quickly breaks out among the Goths, and Rome is unable to supply them with either the food they were promised or the land; they herd the Goths into a temporary holding area surrounded by an armed Roman garrison.

As there is only enough grain left for the Roman garrison, they simply let the Goths starve, offering the trade of slaves (often children and young women) for dog meat.

When Fritigern appeals to Valens for help, he is told that his people will find food and trade in the markets of the distant city of Marcianople.

Having no alternative, some of the Goths trek south in a death march, losing the sickly and old along the path.

When they finally reach Marcianople's gates, they are barred from the city by its military garrison and denied entry.

Next, the Romans make an unsuccessful attempt to assassinate the Goth leaders during a banquet.

Open revolt begins.

The main body of Goths have spent the rest of 376 and early 377 near the Danube plundering food from the immediate region.

Roman garrisons are able to defend isolated forts but most of the country is vulnerable to Gothic plunder.

The Battle of the Willows, the first major conflict of the Gothic War, takes place at a place called ad Salices ("town by the willows"), or according to Roman records, a road way-station called Ad Salices ("By the Willows"); probably located within fifteen kilometers of Marcianople, although its exact location is unknown.

Forces from the Western Roman Empire under the command of Richomeres advance westward, while forces of the Eastern Roman Empire under Trajanus and Profuturus advance northward where they joined forces to attack the Goths.

The battle, ending with nightfall, is a bloody draw with both sides taking many losses; the Goths remain encamped behind their war-wagon circle for over a week after the battle.

In late winter 377, war begins in earnest; the remaining Goths move south from the Danube to Marcianople.

After a battle later in this year, Lupicinus' troops are completely defeated, leaving the Roman territory in the region defenseless.

As a consequence, the Thervings soon rule much of the neighboring, richer province of Thrace.