History of the Greek alphabet retained the sound. A symbol based on the left-hand half ( ├ ) of the letter Η was therefore sometimes used to indicate the presence of where necessary, and its absence was indicated by a symbol based on the right half. During the classical period, ΕΙ came to be pronounced and ΟΥ came to be pronounced , Υ having meanwhile moved to . By about 200 BC, a system of diacritical marks was invented, representing the tone accents in use in Ancient Greek. This also helped to indicate the length of the vowels Α, Ι, and Υ in certain cases
History of the Greek alphabet Daemon”, he describes how Agesilaus king of Sparta, uncovers Alcmene’s tomb at Haliartus and discovers a brazen plate on which a very ancient script was written, much older than the Ancient Greek alphabet. Agesilaus sent a transcript to Egypt in order to be translated back into Ancient Greek. Agetoridas the Spartan travelled to Memphis of Egypt and gave the transcript to Chonouphis the Egyptian priest. Some scholars speculate that this plate was written in Linear B. Agesilaus’ decision to have text sent to Egypt is not unreasonable; it is widely accepted that Ancient Egyptians during the 4th century BC were