Alpes Poeninae (Roman province)

The two centuries of order and prosperity brought by the Pax Romana to Switzerland had ended, as elsewhere in the Empire, with the Crisis of the Third Century.

In 260, when the Gallic Empire had briefly seceded from Rome, the emperor Gallienus had withdrawn the legions from the Rhine to fight the usurper Ingenuus, allowing the warlike Alemanni to enter the Swiss plateau.

Here, cities, villages and most villae have been raided or sacked by marauding bands.

The numerous caches of coins recovered from the period between 250 and 280 attest to the severity of the crisis.

Only the Valais, shielded by mountains, has escaped these predations.

Owing to the constant threat of invasion, the cities in Gaul now construct or reinforce their defensive walls.

The widespread civil unrest during the Crisis of the Third Century has made it no longer safe for merchants to travel as they once had, and the financial crisis that struck has made exchange very difficult.

This has produced profound changes that, in many ways, foreshadow the character of the coming Middle Ages.

Large landowners, no longer able to successfully export their crops over long distances, have begun producing food for subsistence and local barter.

Rather than import manufactured goods, they have begun to manufacture many goods locally, often on their own estates, thus beginning the self-sufficient "house economy" that is to become commonplace in later centuries, reaching its final form in Manorialism.

The common free people of the cities, meanwhile, have begun to move out to the countryside in search of food and protection.

Made desperate by economic necessity, many of these former city dwellers, as well as many small farmers, have been forced to give up basic rights in order to receive protection from large land holders.

In doing so, they have become a half-free class of citizen known as coloni.

They are tied to the land, and in later Imperial law their status will be made hereditary.

This provides an early model for serfdom, which will form the basis of medieval feudal society.

Even the cities themselves have begun to change in character.

The large, open cities of antiquity are slowly giving way to the smaller, walled cities that will be common in the Middle Ages.

These changes are not restricted to the third century, but will take place slowly over long periods of time, punctuated with many temporary reversals.

However, in spite of extensive reforms by later Emperors, the Roman trade network will never be able to fully recover.

The decrease in commerce between the provinces have put them on a path towards increased insularity.

Large landowners, who have become more self-sufficient, have become less mindful of Rome’s central authority and are downright hostile towards its tax collectors.

The measure of wealth at this time begins to have less to do with wielding urban civil authority and more to do with controlling large agricultural estates.

The common people have lost economic and political power to the nobility, and the middle classes have waned.

The Crisis of the Third Century thus marks the beginning of a long evolutionary process that is to transform the ancient world into the medieval one.

Constantine had summoned to Trier the Christian theologian and polemicist Lactantius, to be the tutor of Crispus, who on March 1, 317, is given he title of caesar and made titular ruler of Gaul; Constantine's second son receives the title of Caesar at the same time.

The Diocese of Gaul (Latin: Dioecesis Galliarum, "diocese of the Gaul [province]s"), established in about 314, encompasses northern and eastern Gaul; that is, modern France north and east of the Loire, including the Low Countries and modern Germany west of the Rhine.

The diocese comprises the following provinces: Gallia Lugdunensis I, Gallia Lugdunensis II, Gallia Lugdunensis III, Gallia Lugdunensis IV (Senonia), Belgica I, Belgica II, Germania I, Germania II, Alpes Poenninae et Graiae and Maxima Sequanorum.

Constantine III occupies Arles and established tenuous authority over Gaul, sharing control with marauding "barbarians".

This is generally seen as the beginning of Rome's withdrawal from Britain.

Constantine's two generals Iustinianus and the Frank Nebiogastes, leading the vanguard of his forces, are defeated in 407 by Sarus, Stilicho's lieutenant, with Nebiogastes being first trapped in, then killed outside, Valence.

However, Constantine sends another army headed by Edobichus and Gerontius, and Sarus is forced to retreat into Italy, needing to buy his passage through the Alpine passes from the brigand Bagaudae, who control them.

Constantine secures the Rhine frontier, and garrisons the passes that lead from Gaul into Italy.

Constantine's response to this tightening circle of enemies is a final desperate gamble: encouraged by the entreaties of Honorius' magister equitum, Allobichus, who wants to replace Honorius with a more capable ruler, Constantine marches on Italy with the remaining troops left to him, crossing the Alps into Liguria.

When he learns of the death of Allobichus, whom Honorius had suspected of treachery, Constantine is forced to retreat into Gaul in the late spring of 410.

He is now faced by troops from Spain who have invaded Gaul under Gerontius, who besieges him in Arles.