The ancient Greeks called Cortona the "metropolis of the Tyrrhenians" and long debated its origins, often referring to mythical ancient heroes and peoples. It is certain that the ancient city of Cortona was founded by the Umbrians and later conquered by the Etruscans. Even at this early time, Cortona was mentioned by Livy, along with Perugia and Arezzo, as one of the most important cities in the area.
After the time of the Etruscans, Cortona become a Roman colony and was later occupied by the Goths in 450 A.D. In the period of time following the Goth invasion, Cortona was divided between the Guelph and Ghibelline factions, and endured much internal and external strife, particularly in disputes with nearby Perugia and Arezzo. Following its sack by the army of Arezzo in 1258, Cortona began its ascent as a unified Commune.
By 1312, Cortona was ruled entirely by the Ghibelline family and was established as the center of a Diocese by Pope John XXII in 1325. As the Middle Ages waned, so did the tradition of democracy created by the politically strong guilds of crafts and trade. Consequently, Cortona saw the ascension of the Casali family as dominant rulers and merchants in the area. In 1409, the town was conquered by Ladislaus, King of Naples, who later ceded it in 1411 to Florence, under whose rule it remained until the sieges of the troops of both Clement VII and Charles V. Following these sieges, the town's fate became linked with the Grand Duchy of Tuscany during the 15th century.
The character of the arts, institutions, culture and customs of Cortona were deeply influenced by Florence and the flourishing House of Medici during and after the Renaissance. Illustrious men and women were born and made their home in Cortona. Artists such as Luca Signorelli and Pietro Berrettini, (also known as Pietro da Cortona) ; men of letters such as Garzo; astronomers such as Monetti; and architects such a Jannelli and Laparelli.
Cortona is built on the crest of Monte Sant-Egidio and is surrounded by a massive ancient city-wall that for the most part corresponds to or is made up of walls constructed during the time of the Etruscans. Looking from the top of the city walls, one can see one of the finest and widest views in Italy; the wide fertile plain of the Valdichiana, with the mountains of Siena at the far end and the great shining expanse of Lake Trasimeno in the distance. Large parts of the early Etruscan city walls are visible outside and inside the Porta Montanina (Gate of Montanina), the walls below the Cathedral as far as the Porta S. Maria (Gate of St. Mary) and the area near the Porta Ghibellina (Gate of Ghibelline). The city wall, worn by centuries of wind and weather, has an elongated rectangular form and encircles the perimeter of Cortona. Ancient city gates open out of the city wall onto various roads winding up from the valley below.
Other remains of Etruscan and Roman buildings can still be seen within the city walls; the Etruscan drain near the Porta S. Maria, the Roman-Etruscan drain and Etruscan barrel vault near the Porta S. Agostino, and the Bagni di Bacco Roman baths in the area of the Church of St. Anthony (Chiesa di S. Antonio). Evidence of the Etruscan civilization survives among the impressive religious and secular buildings from the Middle Ages, the Renaissance and beyond. The Chiesa di S. Cristoforo (Church of St. Christopher) is erected on the ruins of an ancient Romanesque parish church.
The architecture of Cortona is often a mixture of periods and styles, revealing layers of history. The Gothic churches of S. Francesco and S. Domenico, the fifteenth century San Niccolo, and the late sixteenth century Santa Maria Nuovo represent typical architectural conventions of their time. The outlying Santa Maria della Grazie al Calcinaio, built beginning in 1483 according to plans created by Francesco di Giorgio Martini, is a noble building of rare elegance, simplicity and harmony. The city's steep ancient streets open up to breathtaking views of the Valdichiana (Chiana Valley) and reveal an urban fabric where houses are built in the light-colored local stone with their upper floors jutting out on wooden corbels. These private dwellings alternate with imposing public buildings such as the Palazzo del Comune and the Palazzo Pretorio. The Palazzo Pretorio has a Renaissance facade and houses the respected Etruscan Academy as well as a valuable, well- known library.
Cortona's painting tradition was dominated by the Sienese tradition throughout the fourteenth and fifteenth centuries. The dramatic Crucifix panel by Pietro Lorenzetti, now in the Museo Diocesano, is an excellent example of the influence of the Sienese school. The Museo Diocesano houses a number of important paintings, the most well-known is Fra Angelico's Annunciaton. The 16th century church of San Niccolo houses fine paintings by the 15th century painter Luca Signorelli.
The flowering of artistry has been constant throughout Cortona's history. A native Cortonese, In the 20th century, a native Cortonese, Gino Severini-the great cubist, futurist and modernist painter, friend of Picasso, Modiglini, Braque and Matisse-returned to Cortona in the years following WWII and created a series of mosaics depicting the Stations of the Cross, which line the steep street of Via Santa Margherita.