The Battle of Mediolanum took place in 259

259

Year 259 was a common year starting on Saturday of the Julian calendar. At the time, it was known as the Year of the Consulship of Aemilianus and Bassus...

, between the Alamannic Germans

Germans

The Germans are a Germanic ethnic group native to Central Europe. The English term Germans has referred to the German-speaking population of the Holy Roman Empire since the Late Middle Ages....

 and the Roman legions under the command of Emperor

Roman Emperor

The Roman emperor was the ruler of the Roman State during the imperial period . The Romans had no single term for the office although at any given time, a given title was associated with the emperor...

 Gallienus

Gallienus

Gallienus was Roman Emperor with his father Valerian from 253 to 260, and alone from 260 to 268. He took control of the Empire at a time when it was undergoing great crisis...

.

Background

As Emperor Valerian

Valerian (emperor)

Valerian , also known as Valerian the Elder, was Roman Emperor from 253 to 260. He was taken captive by Persian king Shapur I after the Battle of Edessa, becoming the only Roman Emperor who was captured as a prisoner of war, resulting in wide-ranging instability across the Empire.-Origins and rise...

, Gallienus´ father, was unable to be present in the battlefield, he named his son Gallienus Emperor. While Valerian was fighting against the Sassanid Empire

Sassanid Empire

The Sassanid Empire , known to its inhabitants as Ērānshahr and Ērān in Middle Persian and resulting in the New Persian terms Iranshahr and Iran , was the last pre-Islamic Persian Empire, ruled by the Sasanian Dynasty from 224 to 651...

 and the Goths

Goths

The Goths were an East Germanic tribe of Scandinavian origin whose two branches, the Visigoths and the Ostrogoths, played an important role in the fall of the Roman Empire and the emergence of Medieval Europe....

, who by that time had sacked Thrace and Asia Minor

Asia Minor

Asia Minor is a geographical location at the westernmost protrusion of Asia, also called Anatolia, and corresponds to the western two thirds of the Asian part of Turkey...

, Gallienus would be in charge of defending the Roman Empire

Roman Empire

The Roman Empire was the post-Republican period of the ancient Roman civilization, characterised by an autocratic form of government and large territorial holdings in Europe and around the Mediterranean....

's border.

In the Western half of the Empire, the situation was difficult. The Danubian

Danube

The Danube is a river in the Central Europe and the Europe's second longest river after the Volga. It is classified as an international waterway....

 border resisted continuous barbarian

Barbarian

Barbarian and savage are terms used to refer to a person who is perceived to be uncivilized. The word is often used either in a general reference to a member of a nation or ethnos, typically a tribal society as seen by an urban civilization either viewed as inferior, or admired as a noble savage...

 attacks. Gallienus had to march with military reinforcements from Gaul

Gaul

Gaul was a region of Western Europe during the Iron Age and Roman era, encompassing present day France, Luxembourg and Belgium, most of Switzerland, the western part of Northern Italy, as well as the parts of the Netherlands and Germany on the left bank of the Rhine. The Gauls were the speakers of...

 towards Dacia

Dacia

In ancient geography, especially in Roman sources, Dacia was the land inhabited by the Dacians or Getae as they were known by the Greeks—the branch of the Thracians north of the Haemus range...

 and Moesia

Moesia

Moesia was an ancient region and later Roman province situated in the Balkans, along the south bank of the Danube River. It included territories of modern-day Southern Serbia , Northern Republic of Macedonia, Northern Bulgaria, Romanian Dobrudja, Southern Moldova, and Budjak .-History:In ancient...

 to fight the Barbarians. The situation was so severe that in 259, the legions of Pannonia

Pannonia

Pannonia was an ancient province of the Roman Empire bounded north and east by the Danube, coterminous westward with Noricum and upper Italy, and southward with Dalmatia and upper Moesia....

 and Moesia rebelled and chose to make Ingenuus

Ingenuus

Ingenuus was a Roman military commander, the imperial legate in Pannonia, who became a usurper to the throne of the emperor Gallienus when he led a brief and unsuccessful revolt in the year 260. Appointed by Gallienus himself, Ingenuus served him well by repulsing a Sarmatian invasion and securing...

 the emperor. Gallienus reunited the Rhine, left Legio II Parthica

Legio II Parthica

Legio secunda Parthica was a Roman legion levied by Emperor Septimius Severus in 197, for his campaign against the Parthian Empire, hence the cognomen Parthica. The legion was still active in the beginning of the 5th century...

to defend it and went off to do battle.

Order of battle

Within the borders of the Rhine and the Alps

Alps

The Alps is one of the great mountain range systems of Europe, stretching from Austria and Slovenia in the east through Italy, Switzerland, Liechtenstein and Germany to France in the west....

, a Germanic confederation

Confederation

A confederation in modern political terms is a permanent union of political units for common action in relation to other units. Usually created by treaty but often later adopting a common constitution, confederations tend to be established for dealing with critical issues such as defense, foreign...

, the Alamanni

Alamanni

The Alamanni, Allemanni, or Alemanni were originally an alliance of Germanic tribes located around the upper Rhine river . One of the earliest references to them is the cognomen Alamannicus assumed by Roman Emperor Caracalla, who ruled the Roman Empire from 211 to 217 and claimed thereby to be...

, who occupied a good part of the Agri Decumates

Agri Decumates

The agri decumates or decumates agri were a region of the Roman Empire's province of Germania superior , covering the Black Forest area between the Main river and the sources of Danube and Rhine rivers, presently in Southwestern Germany...

 (the territory located between the mouth

Mouth

The mouth is the first portion of the alimentary canal that receives food andsaliva. The oral mucosa is the mucous membrane epithelium lining the inside of the mouth....

 of the Rhine river and the Danube), crossed the Alpine steps and attacked the fertile plain of the Po river

Po River

The Po |Ligurian]]: Bodincus or Bodencus) is a river that flows either or – considering the length of the Maira, a right bank tributary – eastward across northern Italy, from a spring seeping from a stony hillside at Pian del Re, a flat place at the head of the Val Po under the northwest face...

. The sacking of the area instilled terror in Rome

Rome

Rome is the capital of Italy and the country's largest and most populated city and comune, with over 2.7 million residents in . The city is located in the central-western portion of the Italian Peninsula, on the Tiber River within the Lazio region of Italy.Rome's history spans two and a half...

, as it was still not a walled city. The Senate of Rome hastily prepared a crowd of plebs for combat in an attempt to ensure that its shrinking army was capable of protecting the city.
Gallienus had just defeated the pretender Ingenuus when the news arrived of the invasion by the Alamanni. He marched off with the legions I Adiutrix

Legio I Adiutrix

Legio prima Adiutrix , was a Roman legion formed in 68, possibly by Galba under orders of Nero. The last record mentioning the Adiutrix is in 344, when it was stationed at Brigetio , in the Roman province of Pannonia...

, II Italica

Legio II Italica

Legio secunda Italica , was a Roman legion levied by emperor Marcus Aurelius in 165 together with I Italica at a time when the Roman Empire was fighting both in Germania and in Parthia. There are still records of the II Italica in Noricum in the beginning of the 5th century...

 and II Parthica to intercept the barbarians in Italy. By then, according to the Byzantine

Byzantine

Byzantine usually refers to the Roman Empire during the Middle Ages.Byzantine may also refer to:* A citizen of the Byzantine Empire, or native Greek during the Middle Ages...

 historian Joannes Zonaras

Joannes Zonaras

Ioannes Zonaras was a Byzantine chronicler and theologian, who lived at Constantinople.Under Emperor Alexios I Komnenos he held the offices of head justice and private secretary to the emperor, but after Alexios' death, he retired to the monastery of St Glykeria, where he spent the rest of his...

, the Alamanni had retreated before the unexpected resistance of the citizens of Rome and its Senate. When Gallienus arrived in the valley of the Po, he found the Alamanni in the vicinity of Mediolanum

Mediolanum

Mediolanum, the ancient Milan, was an important Celtic and then Roman centre of northern Italy. This article charts the history of the city from its settlement by the Insubres around 600 BC, through its conquest by the Romans and its development into a key centre of Western Christianity and capital...

, present day Milan

Milan

Milan is the second-largest city in Italy and the capital city of the region of Lombardy and of the province of Milan. The city proper has a population of about 1.3 million, while its urban area, roughly coinciding with its administrative province and the bordering Province of Monza and Brianza ,...

. The victory was total: according to Zonaras 300,000 Alamanni fell that day and the emperor received the title Germanicus

Germanicus

Germanicus Julius Caesar , commonly known as Germanicus, was a member of the Julio-Claudian dynasty and a prominent general of the early Roman Empire. He was born in Rome, Italia, and was named either Nero Claudius Drusus after his father or Tiberius Claudius Nero after his uncle...

 Maximus.

Aftermath

The Alamanni

Alamanni

The Alamanni, Allemanni, or Alemanni were originally an alliance of Germanic tribes located around the upper Rhine river . One of the earliest references to them is the cognomen Alamannicus assumed by Roman Emperor Caracalla, who ruled the Roman Empire from 211 to 217 and claimed thereby to be...

's success in reaching into the Roman Empire once more revealed the weakness of the centuries-old tradition of posting Rome's legions near the borders without providing for defense within the empire. The battle of Mediolanum demonstrated to the Romans the value of swift, flexible military units. Afterward, Gallienus enacted a major reform by introducing a highly mobile field army composed mainly of cavalry

Cavalry

Cavalry or horsemen were soldiers or warriors who fought mounted on horseback. Cavalry were historically the third oldest and the most mobile of the combat arms...

 (vexillatio

Vexillatio

A vexillatio was a detachment of a Roman legion formed as a temporary task force created by the Roman Army of the Principate. It was named from the standards carried by legionary detachments, vexillum , which bore the emblem and name of the parent legion...

nes). The main units were under the control of his General, Aureolus

Aureolus

For the Frankish ruler of Aragon, see Aureolus of Aragon.Manius Acilius Aureolus was a Roman military commander and would-be usurper. He was one of the so-called Thirty Tyrants who populated the reign of the Emperor Gallienus...

, and headquartered in Mediolanum, with the mission to protect Italy

Italy

Italy , officially the Italian Republic languages]] under the European Charter for Regional or Minority Languages. In each of these, Italy's official name is as follows:;;;;;;;;), is a unitary parliamentary republic in South-Central Europe. To the north it borders France, Switzerland, Austria and...

.

The Roman Senate

Roman Senate

The Senate of the Roman Republic was a political institution in the ancient Roman Republic, however, it was not an elected body, but one whose members were appointed by the consuls, and later by the censors. After a magistrate served his term in office, it usually was followed with automatic...

 had tried to regain its authority by arming and commanding its own military forces to meet the Germanic threat. But, uncomfortable with this challenge to his power, Emperor Gallienus suppressed all of the Senate's military prerogatives.

Finally, the invasion by the Alamanni demonstrated the vulnerability of Italy

Italy

Italy , officially the Italian Republic languages]] under the European Charter for Regional or Minority Languages. In each of these, Italy's official name is as follows:;;;;;;;;), is a unitary parliamentary republic in South-Central Europe. To the north it borders France, Switzerland, Austria and...

 and especially Rome

Rome

Rome is the capital of Italy and the country's largest and most populated city and comune, with over 2.7 million residents in . The city is located in the central-western portion of the Italian Peninsula, on the Tiber River within the Lazio region of Italy.Rome's history spans two and a half...

. This later caused Emperor

Emperor

An emperor is a monarch, usually the sovereign ruler of an empire or another type of imperial realm. Empress, the female equivalent, may indicate an emperor's wife or a woman who rules in her own right...

 Aurelian

Aurelian

Aurelian , was Roman Emperor from 270 to 275. During his reign, he defeated the Alamanni after a devastating war. He also defeated the Goths, Vandals, Juthungi, Sarmatians, and Carpi. Aurelian restored the Empire's eastern provinces after his conquest of the Palmyrene Empire in 273. The following...

to have a strong wall built to defend the capital of the Empire.