The patron saint of Marsicovetere is Saint Bernardino of Siena, celebrated on 20 May: an 18th-century painting of the Neapolitan school depicting him, along with ones of Saint John the Baptist and the Coronation of Mary, adorns one of the Baroque altars of the church of the Holy Apostles Peter and Paul. With the arrival of the Normans the settlement was fortified with a castle and walls: in May 1151 its presence is attested in a deed of donation by which «Alexander Marsici Veteris dominus» granted the monastery of San Giovanni, in the locality of Valloni, to the Abbey of Cava.
On the slopes below today's town, along the Via Herculia leading towards Bari, the powerful Roman family of the Bruttii Praesentes built the Roman villa of Marsicovetere, discovered in 2006 in the Barricelle locality and inhabited from the 2nd century BC to the 7th century AD: monumentalised in the imperial era, it became in the 2nd century the residence of Empress Bruttia Crispina, wife of Emperor Commodus, who came from the Lucanian Bruttii family. The nearest settlement, the Roman city of Grumentum, was instead abandoned and definitively destroyed in 878, according to the tradition reported by the historian Di Meo, when survivors took refuge in hilltop sites such as Tempa San Nicola.
