The Sator Square (or Rotas Square) is a word square containing a five-word Latin palindrome. The earliest form has ROTAS as the top line, but in time the version with SATOR on the top line became dominant. It is a five-by-five square made up of five 5-letter words, thus consisting of 25 letters in total, all derived from eight Latin letters: five consonants (S, T, R, P, N) and three vowels (A, E, O).