There are several meanings of the letters 'IHS'; the most popular being an acronym of the Latin: Iesus Hominum Salvator (Jesus, Saviour of man). Other interpretations include the Latin:
- Jesus Hierosolymae Salvator (Jesus, Saviour of Jerusalem)
- Iesus Habemus Socium (Jesus is our companion)
- In Hoc Signo spes mea (This sign, the cross, is your hope)
- In Hoc Signo Vinces (By this sign you shall conquer)
- In Hoc Salus (Safety)
- German: Iesus Heiland Seligmacher (Jesus, Redeemer and Saviour)
- and English: In His Service (a plagiarism from the British Royal Navy's His/Her Majesty's Ship or the British government's His/Her Majesty's Service, which went out of fashion after James Bond, 007)
However, the most likely meaning is simply the first three letters of 'Jesus' in Greek: ΙΗΣΟΥΣ. The first two characters, iota (Ι) and eta (Η), are almost identical in appearance to the Latin 'IH'. Since there is no Latin character for the third character sigma (Σ), the pronunciation gives us a close approximation to the Latin 'S', giving us the set 'IHS'.
Another transliteration of the sigma (Σ) is 'C', giving us an alternative set 'IHC'. In addition, although there is no 'J' in the Greek alphabet, the first letter is sometimes changed from 'I' to 'J', giving us 'JHS' or 'JHC'. (This latter is thought to have lead to the irreverent expletive 'Jesus H. Christ'.)
The three letters are often shown overlapping, as seen on the gravestone on the right. This photo of an IHS monogram was taken Indian Head, Saskatchewan, Canada.
The letter 'H' can also be seen as a single-runged ladder, symbolising one must take the step of salvation to ascend to heaven (see Ladder Cross.)
The IHS symbol became popular in the Middle Ages, just as the Chi Rho monogram did in Constantine's reign.