Ancient Languages/Greek letters
I recently purchased two old mosaics - one of Mary the Mother of God holding Jesus. On the top left are the initials MP (joined together) and on the right are OV, which I found to mean Mother of God. However, my question is about the other mosaic which is of Jesus Christ. It has initials as well - an ISigma and XSigma. I have researched and only found IC XC on old mosaics of Christ. Therefore I am wondering why they didn't use the usual "C" but instead used the ancient sigma sign.
I can send pictures if it would help. Thanks
the Greek capital letters MP are the abbreviation for the ancient Greek noun MHTHP (in small letters: Μήτηρ transliterated as “Mētēr)) meaning “mother”, while the Greek capital letters ΘΥ (not: OV) are the abbreviation for the ancient Greek noun ΘΕΟΥ (in small letters: Θεού transliterated as “Theou”) meaning “of God”.
In short, the acronym ΜΡ that represents the Greek capital characters Mi (M) and Rho(P), i.e. the first and last letters of MHTHP, and the acronym ΘY that represents the capital Greek characters Theta (Θ) and Ypsilon (Y), i.e. the first and last letters of ΘΕΟΥ) means “Mother of God” since MHTHP/Μήτηρ/Mētēr (nominative case)means "Mother" and ΘΕΟΥ/Θεού/Theou (genitive case) means "of God".
As for the other mosaic which is of Jesus Christ and has the abbreviation “ISigma and XSigma “, please note that “ISigma and XSigma” can be written either as IΣ XΣ or as IC and ΧC with a C which is the so-called “lunate sigma”, an alternate form of the sigma, the 18th letter of the ancient Greek alphabet usually written as Σ in its upper case.
So, IC ΧC or IΣ XΣ are the abbreviations for the ancient Greek words ΙΗΣΟΥΣ ΧΡΙΣΤΟΣ or ΙΗΣΟΥC ΧΡΙΣΤΟC (in small letters: Ἰησοῦς Xριστός, transliterated as "Iesous Christos") meaning “Jesus Christ”.
The acronym IC / IΣ is composed of a Iota (I) and a Sigma (Σ or C) , i.e. the first and last letter of ΙΗΣΟΥΣ / ΙΗΣΟΥC transliterated as IESOUS, while ΧC / XΣ is composed of a Chi (X) and a Sigma (Σ or C), i.e. the first and last letter of ΧΡΙΣΤΟC / ΧΡΙΣΤΟΣ transliterated as CHRISTOS.
To conclude, the lunate sigma C (upper case) -which is known as "lunate sigma" because its crescent shape resembles a half moon and the Latin word for moon is just “luna”- corresponds to the capital letter Σ whose small letter is “σ “ that appears in any position of a Greek word, except for the final letter, where it becomes “ς “ .
Such a lunate sigma began to be used in handwritten Greek during the Hellenistic period (4th and 3rd centuries BC), when the epigraphic form of Σ was simplified into a C-like shape.
This "C" became the universal standard form of Sigma during late antiquity and the Middle Ages and it is still widely used in decorative typefaces in Greece, especially in religious and church contexts as well as in some modern print editions of classical Greek texts.
Hope this is clear enough.