Gaius (praenomen)

Gaius (/ˈɡaɪ.əs/ or /ˈɡeɪ.əs/) is a Latin praenomen, or personal name, which was one of the most common names throughout Roman history. The feminine form is Gaia. The praenomen was used by both patrician and plebeian families, and gave rise to the patronymic gens Gavia. The name was regularly abbreviated C., based on the original spelling of Caius, which dates from the period before the letters "C" and "G" were differentiated.

Throughout Roman history, Gaius was generally the second-most common praenomen, following only Lucius. Although many prominent families did not use it at all, it was so widely distributed amongst all social classes that "Gaius" became a generic name for any man, and "Gaia" for any woman. A familiar Roman wedding ceremony included the words, spoken by the bride, ubi tu Gaius, ego Gaia ("as you are Gaius, I am Gaia"), to which the bridegroom replied, ubi tu Gaia, ego Gaius. The name survived the collapse of the Western Empire in the 5th century, and continued into modern times.

In his epitome, De Praenominibus ("Concerning Praenomina"), Julius Paris states that Gaius is derived from the same root as gaudere, "to rejoice". Although Paris and the unidentified authorities whom he consulted probably relied on folk etymology, modern scholars generally concur with this derivation.

The original form of the name was probably Gavius, in which form it was also used by the Oscans. However, in Latin it had already lost its medial "v" by the time of the earliest inscriptions. An archaic three-syllable pronunciation given above, in which the "a" and "i" are pronounced separately as [ˈɡaː.ɪ.ʊs], is evidence of the original form. This pronunciation persisted, alongside the later two-syllable form in which "a" and "i" are pronounced together as [ˈɡajʊs], throughout the period of the Roman Republic. The existence of the patronymic gens Gavia also suggests the original form of the name, although it could be argued that this family's name was derived from the Oscan praenomen Gavius. But as Gaius and Gavius are apparently based on the same root, this distinction is of limited importance.

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