This river is frequently confused with another river in Italy named Calore. See Calore Lucano

Calore lucano

The Calore Lucano is a river in Campania,southern Italy, whose course is entirely included in the province of Salerno, within Cilento, for a total of about 63 kilometers...

.

The Calore Irpino or Calore Beneventano or Calore River is a river

River

A river is a natural watercourse, usually freshwater, flowing towards an ocean, a lake, a sea, or another river. In a few cases, a river simply flows into the ground or dries up completely before reaching another body of water. Small rivers may also be called by several other names, including...

 in southwestern Italy

Italy

Italy , officially the Italian Republic languages]] under the European Charter for Regional or Minority Languages. In each of these, Italy's official name is as follows:;;;;;;;;), is a unitary parliamentary republic in South-Central Europe. To the north it borders France, Switzerland, Austria and...

. It rises from the Monte Cervialto (1,809 m) in the Monti Picentini

Monti Picentini

thumb|300px|Rocky limestone landscape in the monti Picentini.The Monti Picentini is a mountain range and national park in southern Italy, part of the Apennines, traditionally part in the Campanian Apennines...

 sub-range of the Apennine Mountains

Apennine mountains

The Apennines or Apennine Mountains or Greek oros but just as often used alone as a noun. The ancient Greeks and Romans typically but not always used "mountain" in the singular to mean one or a range; thus, "the Apennine mountain" refers to the entire chain and is translated "the Apennine...

. The river flows first in the province of Avellino

Province of Avellino

The Province of Avellino is a province in the Campania region of Italy. The area is typified by many small towns and villages scattered across the province; in fact only two towns have a population over 20,000; its capital city Avellino and Ariano Irpino....

, and then in that of Benevento

Benevento

Benevento is a town and comune of Campania, Italy, capital of the province of Benevento, 50 km northeast of Naples. It is situated on a hill 130 m above sea-level at the confluence of the Calore Irpino and Sabato...

, before flowing into the Volturno

Volturno

The Volturno is a river in south-central Italy.-Geography:It rises in the Abruzzese central Apennines of Samnium near Rocchetta a Volturno and flows southeast as far as its junction with the Calore River near Caiazzo and runs south as far as Venafro, and then turns southwest, past Capua, to...

. In ancient times it was known as Calor.

On 8 May 663, a large detachment of the army of the Eastern Emperor Constans II, which had invaded the Lombard Duchy of Benevento

Duchy of Benevento

The Duchy and later Principality of Benevento was the southernmost Lombard duchy in medieval Italy, centred on Benevento, a city central in the Mezzogiorno. Owing to the Ducatus Romanus of the popes, which cut it off from the rest of Lombard Italy, Benevento was from the first practically...

, was defeated here in battle by the army of King Grimoald

Grimoald I of Benevento

Grimoald I was duke of Benevento and king of the Lombards .Born probably before 610 to Duke Gisulf II of Friuli and the Bavarian princess Ramhilde, daughter of Duke Garibald I of Bavaria, he succeeded his brother Radoald as duke of Benevento...

, under the joined command of Mitola, Count of Capua, and Grimoald's son, Romuald

Romuald I of Benevento

Romuald I , duke of Benevento was the son of Grimoald, king of the Lombards. He received Benevento when his father usurped the throne in 662. Grimoald sent the deposed king Perctarit's wife Rodelinde and son Cunincpert to the court of his son in Benevento.Romuald betrothed his sister Gisa to...

.

Having already abandoned the siege of Benevento and every small conquest done in Italy, Constans, falling back to Naples

Naples

Naples is a city in Southern Italy, situated on the country's west coast by the Gulf of Naples. Lying between two notable volcanic regions, Mount Vesuvius and the Phlegraean Fields, it is the capital of the region of Campania and of the province of Naples...

, lost any hope to push back the Lombards and re-establish Byzantine sovereignty

Sovereignty

Sovereignty is the quality of having supreme, independent authority over a geographic area, such as a territory. It can be found in a power to rule and make law that rests on a political fact for which no purely legal explanation can be provided...

over southern Italy.