The Sator Square is a three word Latin palindrome, this means that each word forms another word in reverse. What makes the Sator Square unusual is the manner in which the words are arranged so each word will read across or down. In the image the word "opera" has been highlighted. It is widely believed that the Sator Square was a very early Christian symbol. The oldest example was found in the ruins of Pompeii, others have been found throughout Italy and in old English churches. At the time of the destruction of Pompeii (AD 79), Christians were considered enemies of the Roman empire and followers were often persecuted. As a result Christian symbols were either hidden away or coded. The Sator Square is considered by many to be such a coded symbol

Another popular theory is that it is not originally Christian at all. Although the oldest example was found at Pompeii it may have been carved there well before Christianity came into being. Also Christians would have been more likely to use Greek rather than Latin, however, Christians may later have adopted it for reasons we don't yet know. No one knows the true meaning of the words or what they were meant to represent. One suggested meaning of the five words when combined is He who works the plow sows the seed. Others have suggested The Creator of the lands holds the celestial wheels.

The word arepo is the most elusive, it is not considered a Latin word so many scholars believe it to be a name, however no other mention of this name has ever been found. From a numerological point of view the words are interesting in that if we use the base numeric conversion (A = 1, B = 2 etc) each of the words will reduce to 1. From a Chaldean perspective we do not obtain the same symmetry, (8 5 5 5 8).