Assisi is situated on the slopes of Mount Subasio, and it is well known worldwide for being the birthplace of Saint Francis.
A brief history of Assisi
To appreciate the origins of Assisi we first need to visit prehistoric Umbria...
In fact, "the prehistoric definition of Umbria is different from the historical Roman antiquity ... In prehistory it corresponds to a kind of 'channel' between Piceno in the East Adriatic and the Tyrrhenian Sea to the West, not unlike as it is today, with Umbria intermediate between Tuscany and the Marches " .
Assisi came into contact with the Romans after the so-called "Social War" and it then became a "Municipium", a title that it held until the time of Augustus. The evidence of the Romans in Assisi is substantial, such as walls (increased in the Middle Ages), the façade of the Temple of Minerva, the Amphitheatre, the remains of the "Forum" and a painted house, believed to have belonged to Propertius.
After the fall of the Roman Empire, Assisi suffered several damages with the barbarian invasions (such as by Totila in 545) and later in the Lombard period it became part of the Duchy of Spoleto.
The development of Christianity in Assisi is linked to the name of Bishop Rufino (3rd century), to whom the city has dedicated its Cathedral. Around the year 1000, its territory was dominated by a considerable increase in the number of monastic orders, in particular the Benedictines.
It was in this context of a fervent development of the religious spirit, and of training of free municipal institutions, which Assisi saw the development of a strong middle class and wealthy merchants, that, in 1182, Saint Francis was born. He was the son of “Ser Bernardone”, one of the wealthiest merchants of Assisi, who had business relations with France.
Francis, with his name ("Franciscus"), recalls his father's relations with the markets of France and his mother, of French origin. Francis, after a youth in which he practically lived "like a noble," and after witnessing the experiences of soldiers and prisoners, had a "Mystic shock," which led him to abandon the old way of life, devoting himself to an absolute poverty.
The experiment by Saint Francis was also impressive for many who lived around him, and who followed him in his "revolutionary" way of life, which gave life to the Franciscan order, which made many converts both in Italy and abroad. The sanctity of Francis was almost immediately recognized by the Church, in 1228, just two years after his death.
In parallel to this, and still with regard to religious sentiment, the name of Assisi is also linked to Saint Clare (1193-1253), who wished to imitate the Franciscan style and founded the order of "Poor Clares."
Assisi, like all Italian towns of the time, was torn by fierce wars between the Guelphs and Ghibellines, which led to the supremacy of the Guelphs, and in turn a clear dependence by Assisi on the Church State. In the 14th and 15th century, a period of substantial economic and urban growth, Assisi was the centre for many of the greatest soldiers of fortune, like the Visconti, Bracceschi, Sforza and Piccinino.
Around the mid-16th century, Assisi returned to the Church State, until the Unification of Italy (1861) when it became part of modern Italy.
Etymology of the name Assisi
The Romans called it "Asisium" and "Asis" (Propertius [50-15 BC]). But, apparently, "Asisium” was simply the Romanization of a more ancient name, because Assisi, as has been proved by archaeological studies, pre-existed the Roman conquest.
Since it is situated in a location where many people came together from different cultural and linguistic backgrounds (Umbrian, Etruscan and Picenes), it seems unlikely that we can establish the original root of the name "Assisi." In this sense, some scholars have rightly said that the investigation about the etymology of Assisi, at present, “seems stranded in a ‘Limbo of postulates'.
In the past, things seemed much clearer. For example, Domenico Bruschelli wrote with almost absolute certainty that "[...] Assisi, or the Ancients 'Asisium', 'Aesisium' and also 'Assisium', took its name from the mountain 'Asi' or 'Asio', which dominates it.
Multiple and repeated writers supported this claim; 'Asisium' cui super incumbit Mons Asius dictus, a quo traxisse nomen videtur '(Assisi, upon which lies the Mount Asio, from which it seems that it has derived its name "), says John Blaeu. Raffaele Volterra says...: 'Huic Mons imminet Asis, qui oppido dedit nomen' [...] ("This [Assisi] is dominated by the hill 'Asis', which gave its name to the fortified city") .
Today, with the advance of studies, the question, although not resolved beyond all doubt and uncertainty, has taken a step forward. It was established that "Asisium" is of a typical Umbrian linguistic form, and together with another older form, "Asis", which is suggested by a line of Propertius. R. Rossi writes:
"[...] seriously consider the plausibility of the linguistic form 'Asis', certified by Propertius and contemporary to the common form 'Asisium'. 'Asis' thus constitutes the oldest form of the Umbrian town name of Mount Subasio (the pre-Roman origin of the town, of which there is no doubt), while 'Asisium' is the Romanisation of the Umbrian name 'Asis' ... The data that defines Assisi as an Umbrian city are: a) the name of city, b) the language used in official documents, c) the institutions observed until beginning of first century BC [...]" .
Starting from this generally accepted basis, and knowing that the place-names refer to geographical features of the site, such as rivers, streams, mountains and hills, the assumptions, essentially, would be reduced to two. "Asisium" could come from the mountain "Asio", as Bruschelli thought, or from the “Assino” River.
So everything has been resolved? No! Recently a third option was proposed, that, as we saw, now enjoys considerable consideration. According to this hypothesis, "Assisi" means "the city of ‘astore’ [meaning "hawk" or "bird of prey"].”
G. Bonfante writes: "[...] Kretschmer in 'Glotta', XXII, 1934, No 162 has already noted that the name of Assisi, in Latin 'Asisium', belongs to the category of Illyrian names formed with the suffix '-isio' (or '-usio'). These names are usually derived from an animal name, and we have, indeed, 'Brund-isium' and 'Brund-usium', today 'Brindisi' from 'Brund a' ('caput-cervi' [' deer head ']...
...So the character of the Illyrian name 'Asisium' is confirmed as being from 'Asusìa', the name of the Illyrian town called ‘Asseria’ or ‘Aserie’ by Latin authors [...]" 
The possible derivation as "Hawk City" has very ancient origins. In fact the archaeological finds of Assisi site refer to "a pre-Indo-European layer" in close relationship to the Etruscans.
See also Assisi for details of visiting the town
1. See G. Buti-G . Devoto, “Preistoria e Storia delle Regioni d'Italia” [“Prehistory and history of the regions of Italy”], Florence, Sansoni, 1974, p. 93
2. See D. Bruschelli, “Asisi. [sic] Città Serafica e Santuari che la Decorano” ["Assisi. The City and Seraphic shrines that decorate it"], Orvieto, 1824, p. 6
3. See R . Rossi, “Storia Illustrata delle città dell'Umbria” ["Illustrated History of the towns of Umbria"], Sellino, 1997, p. 9, p. 261
4. See G. Bonfante, “I nomi di Assisi e di Capua” ["The names of Assisi and Capua,"] in "Italica", Vol 20, No. 4 (Dec. 1943), pp. 189-196, “American Association of Teachers of English”, and http://www.jstor.org/stable/476476 footnote 1