According to legend, Rufinus of Assisi (Italian: Rufino), was the first bishop of this city and a martyr.

He is probably identical with the "episcopus Marsorum" (bishop of the Marsi) noted in the Roman Martyrology under 11 August.

At some point, the Roman proconsul, Aspasius, had him arrested, tortured, and drowned in the Chiascio River near Costano.

A church was built on that spot[2] from whence, according to Petrus Damiani, his relics were translated to Assisi in the 8th century.

It is now located under the main altar of the Cathedral of San Rufino, which is the third church to have been erected over his remains.