The Cumae alphabet was a special Greek alphabet, considered to be a variation of the alphabet used in Chalkis. It was used in Cuma, an ancient Euboean Greek city, recently excavated in 1992, and in Cumae, a Greek colony in Italy.
In the Cumae alphabet, the Greek letter Σ was written as C, Δ as D, Ξ as Χ, Ρ as R and Υ as U.
It is very possible that the Latin alphabet derived from this one.
