The Battle of Lugdunum

[Imperial Dave]

The Battle of Lugdunum Was the Largest Battle in Roman History | TheCollector https://share.google/aEsAvj0C7hk8CrNx7

Didn't realise it was the largest...

[Ian61]

This could be title hype again. 'Possibly' the biggest between two Roman forces, that is civil war type events.

[Adrian Nayler]

The most well-known account of the battle of Lugdunum comes from Dio-Cassius and contains the figure of 150,000 men in the armies. The other account, lesser known, is that of Herodian who was a contemporary of Dio. Herodian was evidently no great fan but, none-the-less, he summarises the achievement of Severus as follows (my parentheses):

"The emperor thus won two magnificent victories, one in the East (against Niger) and one in the West (against Albinus). No battles and no victories can be compared to those of Severus, and no army to the size of his army; there are no comparable uprisings among nations, or total number of campaigns, or length and speed of marches." Herodian, Ab Excessu Divi Marci III.7. 

Whatever the actual numbers concerned it does seem that Romans thirty to forty years after the events thought they were very big indeed.

Echols, E.C. (translator) (1961) Herodian of Antioch's History of the Roman Empire, University of California Press.

[Imperial Dave]

And again I profess my lack of knowledge on the battle so indebted to others for their thoughts

[Nick Harbud]

Severus's battles were an obvious black and white case.   

[Keraunos]

"The emperor thus won two magnificent victories, one in the East (against Niger) and one in the West (against Albinus). No battles and no victories can be compared to those of Severus, and no army to the size of his army; there are no comparable uprisings among nations, or total number of campaigns, or length and speed of marches." Herodian, Ab Excessu Divi Marci III.7. 

Sounds like a modern day press release from the bling palace formerly known as the White House.