De Mario Surname in Italy

The surname De Mario originates from the medieval personal name Mario, whose spread in Italy is partly due to the veneration of the Virgin Mary. Although it was long believed that Mario was simply the masculine form of Maria, its true origin is pre-Christian, and its current meaning remains uncertain and debated. This surname thus developed as a patronymic derived from the given name of the founding ancestor. Geographically, De Mario has distinct historical centers: one in the Belluno area around Santo Stefano di Cadore, and another in the Bari area including Valenzano, Capurso, and Bari itself. The variants Demario and Dimario are quite rare, while Di Mario shows significant concentration in Lazio, Abruzzo, and Molise, especially in the provinces of Rome and Frosinone, with additional clusters in the Bari area and eastern Sicily.