Early origins of Arintha - Castiglione
On the antiquity of Castiglione in Calabria, in the 19th century, V. Padula believed that the town was the heir to the ancient city of “Arithia” following the line of towns: Arithia -> Arintha -> Arianthe -> Castiglione.
According to Hecataeus of Miletus (550-476 BC), ‘Arithia’ was an Oenotrian town located between two rivers. Therefore, there is no doubt that the ancient ‘Arintha’ is the modern town of Castiglione, located between the Corno and Arente rivers. Arintha derived its name from the river ‘Arente’ on which it was situated and ‘Arente’ corresponds to the Chaldean name ‘Arith’ which means ‘stream’ .
However, it seems that Arintha is to be identified with Rende, near Castiglione, and contemporary history studies are inclined to believe that the town was built in much more recent centuries, hence not related to the earlier town of Arithia - because, apparently, Castiglione was founded around the 9th or 10th century during the periods of the Saracen raids on Italy. So this hypothesis states that Castiglione had arisen, together with most of the so-called “Casali di Cosenza”, around the ninth century, at the time of the raids of the Saracens, when the inhabitants of Cosenza were trying to escape from their city.
Another interesting hypothesis identifies Castiglione with an ancient village called “Guarano”:
“It seems that formerly it was called ‘Guarano,’ a linguistic corruption of the term ‘Arano,’ used in the sense of ‘place inhabited by primitive peoples.’ It was called ‘Castiglione’ until 1863 when a royal decree added the specification “Cosentino”, to distinguish it from the towns of the same name. The first part of the name presumably derives from ‘castello’ [=castle]; there is, however, reason to believe that the modern name should be connected with the name of the “Castiglioni”, belonging to the feudal nobility of this Country. Towards the middle of the 15th century Castiglione was conquered, plundered and burned by the troops of King Ferrante of Aragon (1431-1494), who wished to send a warning to unfriendly towns. Serious damage was also suffered during the occupation of the French" .
Castiglione Cosentino from the 11th century
According to recent studies, "Castellione" was built at the beginning of the 11th century, after the incursions of the Saracens, who occupied and devastated Cosenza: the city's inhabitants sought refuge in safer places, and many fortified places such as Carpanzano, Casole Bruzio, Castiglione Cosentino, Celico, Dipignano, and others were built. It seems that “about 100 villages, called ‘Casali’, were built” : “These villages were considered by the inhabitants of Cosenza as neighbourhoods of their city" .)
Later, the Castiglione Family, awarded the title of marquis, kept possession of it until the abolition of feudalism.
Castiglione was under the rule of the Swabians until the second half of the 13th century and under the Angevins until 1435; in fact, the town is mentioned in the Angevin taxation of 1276, under the name of "Guarano."
In the Kingdom of Naples the Aragonese followed the dynasty of the Angevins, who deprived some of the local nobles of their privileges. Among the nobles who were deprived of their privileges we find the Castiglione, who became the most fierce opponents of the Aragonese. In Calabria a serious revolt arose, led by Antonio Centelles against the Aragonese. Hence in 1460 King Ferdinand I (1423-1494) attacked Castiglione Cosentino where the rebels had taken refuge:
"Castiglione Cosentino was put to fire and sword and, after the surrender, it was completely destroyed by the flames, and the leaders of the rebellion were sentenced to pay a large fine" 
From that point onwards the history of Castiglione Cosentino followed the events of Cosenza, until the Unification of Italy in 1861. Among the important local historical data, we remember that the town was subject to frequent earthquakes between the 17th and 20th centuries with results that were sometimes very serious for the architectural heritage.
The town took the name of "Castiglione Cosentino" in 1862.
Origins of the name Guarano
With regard to the etymology of “Guarano,” V. Peruta derived the name from the term “Charan” in the meaning of “volcanic soil” subject to earthquakes. Explaining the name of San Pietro a Guarano, a village near Castiglione, V. Padula wrote:
"S. Pietro a Guarano derived from ‘Charan,’ Latin ‘adustus’ [burnt] and that it really was a burned place is demonstrated by the fact that there was a volcano" ..
Instead, according to the most recent studies, “Gualano” would simply mean “young keeper of oxen.” Linguists now agree on this hypothesis: "‘Gualano,’ ‘gualanorum,’ ‘gualani’ (= young keeper of oxen]" .
F. Sabatini excluded both a Latin, “Aequalanus” [=herdsman] and a Lombard origin [ “gualdemannus” or 'gualdus' = wood, from 'wald']. He proposed instead a Provencal origin from “Galan,” which in time derived from the French term “Galant,” meaning “young.” These names are attested to in some Angevin documents from the end of the 13th century. Among other things, the Angevins in the kingdom of Naples organized a system of royal farms.
Origins of the name Castiglione
As we have seen, it seems that “Castiglione” derives from the “Castiglione” family, which owned it in the 13th century. However, already by the 17th century A.D. Branciforte was not convinced that the name derived from the family of Castiglione, but from "Castellione" [= big castle], with reference to the fact that there existed an ancient and mighty fortress:
"Bernardino Marciano said that Castiglione was an ancient town, which was called 'Castelleone' because of the presence of a castle [...] Later underwent a linguistic corruption and the town was called 'Castiglione'. In my opinion the name does not come from the family of the Castiglione, who ruled the city for a long time" 
See visitor information at Castiglione Cosentino guide
1. See Padula, “Protogèa. L'Europa preistorica”, Napoli, 1871, p. 407
2. See G. Falasca, “Calabria”, Istituto enciclopedico italiano, 2002, p. 48
3. See V. Padula, pp. 406-407
4. See F. Sabatini, , “L'italiano meridionale. Gualano”, in “lingua Nostra”, XXV, 1964, p. 46, e ancora F. Sabatini, “L'Italiano meridionale e Gualano”, in “Italia linguistica delle origini...”, 1996, p. 372
5. See D.C. Branciforte, “Della Calabria illustrata”, Napoli, 1691, Tomo I, p. 123
6. See “Tra Calabria e Mezzogiorno”, edited by G. Masi, Pellegrini, 2007, p. 113 footnote 5
7. See R. Giraldi, “Il popolo cosentino e il suo territorio”, Pellegrini, 2003, p. 61
8. See“Almanacco Calabrese”, 1964, p. 70 e P. Ebner, “Chiesa, Baroni e popolo nel Cilento”, Roma, Edizioni di storia e letteratura, Vol. I, p. 82 footnote 16