In 356 AD, Roman

Ancient Rome

Ancient Rome was a thriving civilization that grew on the Italian Peninsula as early as the 8th century BC. Located along the Mediterranean Sea and centered on the city of Rome, it expanded to one of the largest empires in the ancient world....

 Emperor Julian the Apostate

Julian the Apostate

Julian "the Apostate" , commonly known as Julian, or also Julian the Philosopher, was Roman Emperor from 361 to 363 and a noted philosopher and Greek writer....

 over-wintered in Senonae

Senonae

Senonae is a settlement of uncertain location in Roman Gaul. It may have been the capital of the Senones tribe, the present city of Sens on the Yonne in the Bourgogne, or a location in the present commune of Senon. Julian the Apostate wintered there on his campaign against the Alamanni in the Rhine...

 (possibly modern Sens

Sens

Sens is a commune in the Yonne department in Burgundy in north-central France.Sens is a sub-prefecture of the department. It is crossed by the Yonne and the Vanne, which empties into the Yonne here.-History:...

) in 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...

. Following desertion

Desertion

In military terminology, desertion is the abandonment of a "duty" or post without permission and is done with the intention of not returning...

s from his German federated troops

Foederati

Foederatus is a Latin term whose definition and usage drifted in the time between the early Roman Republic and the end of the Western Roman Empire...

, hostile Germanic warbands learned that his force was under-strength and moved to attack the town. However, they were not able to break into the town, lacking advanced siegecraft, and could only prevent Julian from venturing outside the walls. After a month, they withdrew.