Linear A is one of two scripts used in ancient Crete before Mycenaean Greek Linear B; Cretan hieroglyphs is the second script. In Minoan times, before the Mycenaean Greek dominion, Linear A was the official script for the palaces and religious activities, and hieroglyphs were mainly used on seals. These three scripts were discovered and named by Arthur Evans. In 1952, Michael Ventris discovered that Linear B was being used to write the early form of Greek known as Mycenaean. He and others used this information to achieve a significant and now well accepted decipherment of Linear B, although many points remain to be clarified. By contrast, Linear A has not been deciphered since the language of Linear A has not been discovered. - Halil from Bookmarklet

Though the two scripts – Linear A and B – share some of the same symbols, using the syllables associated with Linear B in Linear A writings produces words that are unrelated to any known language. This language has been dubbed Minoan and corresponds to a period in Cretan history prior to a series of invasions by Mycenaean Greeks around 1450 BC. Linear A seems to have been used as a complete syllabary around 1900–1800 BC, although several signs appear earlier as mason marks. It is possible that the Trojan Linear A scripts that were discovered by Heinrich Schliemann and one inscription from central Crete, as well as a few similar potters' marks from Lahun, Egypt (12th dynasty), come from an earlier period, ca. 2100–1900 BC, which coincides with the construction of the first palaces. - Halil