Battle of Lutetia

[7] He captured the oppidum of Metlosedum (possibly present-day Melun), and crossed the Seine to attack the Gallic coalition near Lutetia.

Threatened by the Bellovaci (a powerful Belgae tribe), he decided to re-cross the Seine to rejoin Caesar's force at Agedincum (Sens).

After the two sides engaged the Seventh legion, placed on the right wing, started to push back the Gallic left.

The turning point came when the military tribunes of the Seventh legion led their legionaries against the enemy rear.

[9] After linking up with the five cohorts he had used as a diversion, Labienus marched his army back to Agendicum where he met up with Caesar returning from his defeat at Gergovia.

Map centered on France. From the previous year, territory has expanded all the way to the Rhine river.
Campaign map 52 BC. Most of southern and central Gaul is in revolt. Note Labienus (2) for Labienus's Lutetia campaign