| Siege of Tortona | |||||||
|---|---|---|---|---|---|---|---|
| Part of Guelphs and Ghibellines | |||||||
| |||||||
| Belligerents | |||||||
|
Holy Roman Empire Commune of Pavia Margraviate of Montferrat |
Commune of Tortona Commune of Milan | ||||||
| Commanders and leaders | |||||||
| Frederick I, Holy Roman Emperor | Obizzo Malaspina | ||||||
| Strength | |||||||
|
5,400–7,200+ 5,400–7,200
Montferrat's forces |
300+ 100 knights 200 archers Tortonian militia Malaspina's men | ||||||
| Casualties and losses | |||||||
| Unknown |
Garrison captured City burned | ||||||
  Location within Italy  Siege of Tortona (Mediterranean) | |||||||
The siege of Tortona in 1155 was the first major military engagement resulting from Holy Roman Emperor Frederick Barbarossa's ambition to enforce Imperial hegemony in Italy.