Assisi became a Roman municipium called Asisium. In 238 AD, Bishop Rufino introduced Christianity. Conquered by the Goths of Totila in 545, it became part of the Lombard and Frankish Duchy of Spoleto.
In the 11th century, Assisi became a free Ghibelline commune, often in conflict with Guelph of Perugia. In 1189, the people of Assisi attacked the imperial fortress but were defeated by Perugia at Ponte San Giovanni. Among the prisoners was Giovanni di Bernardone, the future Saint Francis.
After his captivity, Francis renounced his wealth and, in 1205, had a vision in San Damiano, which led him to rebuild the Church. In 1208, he founded the Order of the Friars Minor, followed in 1212 by the Order of Poor Clares with Saint Clare. In 1221, he established the Third Order for laypeople. In 1224, he received the stigmata at La Verna and died in 1226 in Porziuncola. Canonized in 1228, the Basilica of Saint Francis was built in his honor. Saint Clare was also canonized and her church was constructed in 1254.
In 1316, Assisi expanded its domain, but after the plague of 1348 began its decline began. To strengthen papal control, Cardinal Egidio Albornoz built the Rocca Maggiore (1367). From the 14th to the 16th century, the Nepis and Fiumi families fought for power while the city passed under various different rulers. It was only under Pope Pius II Piccolomini (1458-1464) that Assisi was permanently restored to Papal control.