a very ancient patrician gens, which traced its origin to the mythical Gyas, one of the companions of Aeneas. (Serv. ad Virg. Aen. 5.117.) According to both Livy (1.30) and Dionysius (3.29), the Geganii were one of the most distinguished Alban houses, transplanted to Rome on the destruction of Alba by Tullus Hostilius, and enrolled among the Roman patres. The name, however, occurs even in the reign of Numa, who is said to have chosen Gegania as one of the vestal virgins. (Plut. Num. 10.) Another Gegania is mentioned as the wife of Servius Tullins (Plut. de Fort. Rom. p. 323), or of Tarquinius Priscus (Dionys. A. R. 4.7); and a third Gegania occurs in the reign of Tarquinius Superbus. (Plut. Comp. Lyc. c. Num. 3.)
There appears to have been only one family in this gens, that of MACERINUS,many members of which filled the highest offices in the state in the early times of the republic. The last of the family who is mentioned is M. Geganius Macerinus, who was consular tribune in B. C. 367; and from that time the name of Geganius does not occur at all in history till the year B. C. 100, when we read of one L. Geganius who was killed along with Cn. Dolabella, the brother of Saturninus, in the troubles occasioned by the seditious schemes of the latter. (Oros. 5.17.)