Ab urbe condita

Titus Livius (Livy)

Livy. History of Rome, Volumes 1-2. Roberts, Canon, Rev, translator. London, New York: J. M. Dent and Sons; E. P. Dutton and Co., 1912.

—was the cause of the error, and that a story in which the lists of both elections were combined was constructed to fit in with the mistake.