Xi (letter) Xi (letter) Xi (uppercase Ξ, lowercase ξ; ) is the 14th letter of the Greek alphabet. It is pronounced in Modern Greek, and generally or in English. In the system of Greek numerals, it has a value of 60. Xi was derived from the Phoenician letter samekh . Xi is not to be confused with the letter chi, which gave its form to the Latin letter X. Both in classical Ancient Greek and in Modern Greek, the letter Ξ represents the sound . In some archaic local variants of the Greek alphabet, this letter was missing. Instead, especially in the
History of the Greek alphabet the Latin alphabet. Most specialists believe that the Phoenician alphabet was adopted for Greek during the early 8th century BC, perhaps in Euboea. The earliest known fragmentary Greek inscriptions date from this time, 770–750 BC, and they match Phoenician letter forms of c. 800–750 BC. The oldest substantial texts known to date are the Dipylon inscription and the text on the so-called Cup of Nestor, both dated to the late 8th century BC, inscriptions of personal ownership and dedications to a god. Tradition recounts that a daughter of a certain Agamemnon, king of Aeolian Cyme, married a Phrygian king called