The patroness of Aquila d'Arroscia is Saint Reparata, celebrated on 8 October. The parish church dedicated to her, in the main village, was built between 1582 and 1589, and its consecration is said to date precisely from 8 October 1597; the Baroque façade was completed in 1625, while the wooden choir held inside comes from the Augustinian convent of Pieve di Teco.
The village of Aquila and other places in the Arroscia valley came, from 1202, under the Marquisate of Clavesana, an ally of the Republic of Genoa: it was the marquises who erected the local castle around the 11th century, on a rocky summit close to the town. According to popular legend, the place name Aquila (Eagle) derives precisely from this bird of prey, which usually settled near the hill later called «dell'Aquila»; another version, considered more plausible, places its origin elsewhere. In 1328 the village and castle were occupied by Marquis Giorgio Del Carretto, who took the holding from the Clavesana vassal Oberto Cepolla, only for it to return later among the marquisate's territories; in 1386 the territory passed under the direct control of the Republic of Genoa, which placed Aquila first in the vicariate of Ranzo and then in the captaincy of Pieve di Teco. Of the castle, built around 1090, only ruins remain today, but the old crenellated walls and the four sides of the truncated polygonal tower are still visible.
