Rex Sacrorum - Regina Sacrorum

As the wife of the rex sacrorum, the regina sacrorum ("queen of the sacred rites") was a high priestess who carried out ritual duties only she could perform. On the Kalends of every month, the regina presided at the sacrifice of a sow (porca) or female lamb (agna) to Juno. The highly public nature of these sacrifices, like the role of the Vestals in official Roman religion, contradicts the commonplace notion that women's religious activities in ancient Rome were restricted to the private or domestic sphere. Unlike the Vestals, however, the regina sacrorum and the flaminica Dialis (the wife of the flamen Dialis or high priest of Jupiter) were complements to a male partner; these two priesthoods were gender-balanced and had shared duties.

While performing her rituals, the regina wore a headdress called the arculum, formed from a garland of pomegranate twigs tied up with a white woolen thread. The rex and regina sacrorum were required to marry by the ritual of confarreatio, originally reserved for patricians, but after the Lex Canuleia of 445 BC, it is possible that the regina could have been plebeian.

Inscriptions record the names of a few reginae sacrorum, including Sergia Paullina, the wife of Cn. Pinarius Cornelius Severus, shortly before 112 AD, and Manlia Fadilla around the 2nd/3rd century AD.