Suetonius tells in the book dedicated to Claudius of his Life of the Twelve Caesars that this invented three letters that he believed were of great need and which he wanted to add to the alphabet. Before he became emperor he had already published a book on this subject; when he was, he did not encounter great difficulties in adopting the use of such letters that are found in most of the books, public acts and inscriptions of that time .
Claudius, who was a scholar and wrote numerous works throughout his life (including an Etruscan history and dictionary, and eight volumes on Carthage) all now lost, proposed the reform of the alphabet at the same time that he tried to return to the ancient habit of putting periods between words. And it is that classical Latin was written without leaving spaces between them.
He did so using the office of censor, possibly purposely imitating the example of his ancestor Appius Claudius Ceco. This can be considered as the first famous personality in Roman history, whose position as censor he assumed in the year 312 BC. resulting in quite a political sensation.
He not only built the Via Appia and the aqueduct known as Aqua Appia, but also managed to have it named after him in an unprecedented way. His story would give for a long article, but what is interesting here is that he also made changes to the Latin alphabet. He is credited with inventing the letter r and, according to Martianus Capella (De Nuptiis Philologiae et Mercurii, III, 261), it was he who eliminated the letter Z from the Latin alphabet and introduced in its place a new one, the G (to denote the K sound in words like Gaius or Gnaeus ). However, Plutarch attributes this last invention to Spurius Carvilius Ruga, who would have invented the G by adding a new stroke to the C.
The letter Z had already been reintroduced into Latin before the time of Claudius, after the conquest of Greece in the 1st century BC, though only to represent the sound in words borrowed from the Greek. However, since its place had been taken by G, it was relegated to the end of the alphabet.
Tacitus (Annals XI, 13–14) also accounts for the three new letters added by Claudius:
The letters in question were the inverted digamma , the antisigma and the mean H , but as Tacitus says, they were only used while he ruled and then they disappeared forever.
The inverted digamma it was written Ⅎ, as an F rotated 180 degrees, and served to represent the sound of V (/w/), leaving the letter V for the sound /u/.
The anti-sigma it was written Ↄ or ↃϹ, and represented the sound of the digraphs BS and PS, just as the X represented those of CS and GS.
The mean H it was written Ⱶ, and was used to represent the sound between /u/ and /i/, similar to the German ü. Later, after the death of Claudius, the letter Y would be reintroduced in the Latin alphabet, to transcribe the Greek words that contained the sound represented by the middle H .
Although the three letters fell out of use in the first century AD, we can use them today thanks to their inclusion in the Unicode standard, the character encoding system used by our computer software.