Editing 222 BC (section)

==== Roman Republic ====
* The [[Roman Republic|Roman]] [[consul|consuls]] [[Marcus Claudius Marcellus]] and [[Gnaeus Cornelius Scipio Calvus]] march into [[Insubres]] territory and besiege [[Acerrae (Cisalpine Gaul)|Acerrae]], an Insubre fortification on the right bank of the River [[Adda River, Italy|Adda]] between [[Cremona]] and [[Laus Pompeia]]. The Insubres are unable to relieve Acerrae because the Romans control all the strategic points around it. Therefore, they hire 30,000 [[Gaesatae]] mercenaries, led by [[Viridomarus]] (or Britomartus), who march to [[Clastidium]], an important and strategically situated town, owned by the [[Marici (tribe)|Marici]], a [[Ligures|Ligurian]] tribe allied to the Romans, they start a siege hoping that this will force the Romans to lift their siege of Acerrae to come to Clastidium's aid.<ref>[[Polybius]], The Histories, 2.19-20</ref>
*The Romans split their forces. [[Marcus Claudius Marcellus]] heads for [[Clastidium]] while his colleague [[Gnaeus Cornelius Scipio Calvus]] continues the siege of [[Acerrae (Cisalpine Gaul)|Acerrae]]. At the [[Battle of Clastidium]] Marcellus defeats the [[Gaesatae]]. Marcellus personally slays [[Viridomarus]]. This victory removes the Gallic threat to Rome. Marcellus is awarded the [[spolia opima]] for the third and last time in Roman history.<ref>[[Polybius]], The Histories, 2.19; [[Plutarch]], ''Marcellus'', 6-7.</ref>
* After taking Acerrae [[Gnaeus Cornelius Scipio Calvus]] marches on [[Mediolanum]] (modern [[Milan]]), another [[fortification|stronghold]] of the [[Insubres]], which also falls into [[Roman Republic|Roman]] hands, upon which the chieftains of the Insubres lose all hope and [[Unconditional surrender|surrendered unconditionally]].  Thus the Romans succeeded in conquering the largest independent Celtic tribe in Italy and firmly established their hegemony over the [[Po Valley]], then the most productive agricultural region in the peninsula.<ref>[[Polybius]], The Histories, II 17,4-5 and 20.</ref>