Caius

Caius is an Anglicized form of the Latin praenomen Gaius, used in English-speaking contexts to refer to figures from ancient Rome as well as later ecclesiastical and scholarly individuals. In Latin, Gaius was one of the most common praenomina and appears in many Roman names; the form Caius emerged in medieval Latin and English texts and continues to appear in modern usage, especially in historical or biographical contexts. The spelling Caius is also preserved in institutional names and literary references.

Notable historical uses include Pope Saint Caius (Gaius), who presided as pope from about 283 to 296 and is venerated in the Catholic tradition; and John Caius (1510–1573), an English physician after whom Gonville and Caius College, Cambridge, is named. The college was founded in 1557 and remains one of Cambridge University's constituent colleges.

In contemporary culture, Caius appears as a given name in fiction and media, such as Caius Ballad, a major character in Final Fantasy XIII-2. More generally, Caius continues to be used as a surname or given name among English-speaking populations, often in reference to its classical roots.

See also Gaius, Gaio, and related variants, which reflect the same Latin origin but different transliterations or adaptations.