Acerrae was ‘a city of Cisalpine Gaul

Cisalpine Gaul

Cisalpine Gaul, in Latin: Gallia Cisalpina or Citerior, also called Gallia Togata, was a Roman province until 41 BC when it was merged into Roman Italy.It bore the name Gallia, because the great body of its inhabitants, after the expulsion of the Etruscans, consisted of Gauls or Celts...

, in the territory of the Insubres

Insubres

The Insubres were a Gaulish population settled in Insubria, in what is now Lombardy . They were the founders of Milan . Though ethnically Celtic at the time of Roman conquest , they were most likely the result of the fusion of pre-existing Ligurian, Celtic and "Italic" population strata with Gaulish...

. Polybius

Polybius

Polybius , Greek ) was a Greek historian of the Hellenistic Period noted for his work, The Histories, which covered the period of 220–146 BC in detail. The work describes in part the rise of the Roman Republic and its gradual domination over Greece...

 describes it merely as situated between 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....

 and the Po

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...

; and his words are copied by Stephanus of Byzantium

Stephanus of Byzantium

Stephen of Byzantium, also known as Stephanus Byzantinus , was the author of an important geographical dictionary entitled Ethnica...

: but Strabo

Strabo

Strabo, also written Strabon was a Greek historian, geographer and philosopher.-Life:Strabo was born to an affluent family from Amaseia in Pontus , a city which he said was situated the approximate equivalent of 75 km from the Black Sea...

 tells us that it was near Cremona

Cremona

Cremona is a city and comune in northern Italy, situated in Lombardy, on the left bank of the Po River in the middle of the Pianura Padana . It is the capital of the province of Cremona and the seat of the local City and Province governments...

: and the Tabula

Tabula Peutingeriana

The Tabula Peutingeriana is an itinerarium showing the cursus publicus, the road network in the Roman Empire. The original map of which this is a unique copy was last revised in the fourth or early fifth century. It covers Europe, parts of Asia and North Africa...

 places it on the road from that city to Laus Pompeia (Lodi Vecchio), at a distance of 22 Roman miles from the latter place, and 13 from Cremona. These distances coincide with the position of Gherra or Gera, a village, or rather suburb of Pizzighettone, on the right bank of the river Adda

Adda River

The Adda is a river in North Italy, a tributary of the Po. It rises in the Alps near the border with Switzerland and flows through Lake Como. The Adda joins the Po a few kilometres upstream of Cremona. It is 313 kilometres long...

. It appears to have been a place of considerable strength and importance (probably as commanding the passage of the Adda) even before the Roman conquest: and in B.C. 222, held out for a considerable time against the consuls Marcellus

Marcellus

-In Christianity:* Marcellus of Ancyra , bishop* Pope Marcellus I, saint* Pope Marcellus II, Italian pope* Marcellus of Tangier , martyr* Pseudo-Marcellus, author of the Passio sanctorum Petri et Pauli...

 and Scipio

Scipio

-Classical:* Scipio, a representation of the Cornelii Scipiones, branch of the illustrious Cornelii family from Ancient Rome.* Scipio Africanus, Roman general who defeated Hannibal at Zama, the final battle of the Second Punic War....

, but was compelled to surrender after the battle of Clastidium

Battle of Clastidium

The Battle of Clastidium was fought in 222 BC between a Roman Republican army led by the Roman consul Marcus Claudius Marcellus and the Insubres led by Viridomarus. The Romans won the battle, and in the process, Marcellus earned the Spolia opima, one of the highest honors in ancient Rome, by...

.’