The first attempts at a written language were made, not by the Maya, but the Olmecs, along with the calendar and mathematic systems. Granted, the Olmecs went only so far with these concepts before their eclipse around 1200 B.C. The Maya shortly thereafter picked up the ball and ranárefining and expanding these systems in an unprecedented way. By 250 A.D. writing was widespread throughout the Maya world and was visible on carved stone monuments, pottery, wall paintings, and almost certainly bark-paper books that did not survive. The Maya script is not a code at all, but rather a graphic system for expressing a language-oriented message. Codes are encrypted writings, not intended to be read by just anyone and are therefore secret in nature. Not the sort of thing to put on a public monument. Many scholars were convinced that the Maya script could be understood if somehow a key to the glyphs could be found. Shortly after World War Two, the team of expert code-breakers that had cracked the Japanese Naval Code were brought in to "break the code". Years later the entire team passed on without having solved a single glyph.
There are about 800 signs in the Maya hieroglyphic script, but given the range of variability of scribes, many of these may be variations of the same glyph. Then too, many of the symbols are what is known as a logogram, such as the name of a ruler whose name might appear once or twice in the written record and then disappear. Some symbols have the same meaning and others have more than one meaning. Most epigraphers argue that somewhere between 200 and 300 glyphs were in general use at any given time in Maya history. With the relatively few symbols and knowledge of the 30 Maya languages currently being spoken, what is the problem? Why has the decypherment stumped some of the world's most powerful linguistic intellects for two centuries?
Very simply stated, the glyphs contain several components. Some make use of pictures of objects to convey meaning along with syllables made up of two or more sounds or phonemes. Phonemes are derived from the Maya language of the period and region. English, for example has 26 letters in the alphabet but over 40 sounds or phonemes. Consider the "sh" or "ch" sounds in "shut" and "church." Now in order to understand the language components in the glyphs it is necessary, naturally, to know which language the sounds were derived from. As Shakespeare would say "therein lies the rub."
Of the existing Maya languages, scholars cannot be sure which evolved from the Maya language of the Maya script. At the close of the Classic period in Maya history, the scribes who were a part of the ruling elite class faded into obscurity and the writing went with them. The last carved stone monument was erected in 889 A.D. Consequently, it is not possible to trace the evolution of languages until the reintroduction of writing by the Europeans. In English we have a written record that takes us back through Chaucer and even to Beowulf, which one can hardly recognize today as a precursor to modern English.
In spite of these formidable odds, epigraphers have made significant gains in the last few years. Glyphs pertaining to various parts of speech have been identified. Symbols for social and historic importance have been isolated, such as those glyphs for birth, death, ascension to the throne, marriage and personal names and titles.
It's anybody's guess just how many more symbols will be identified in the future given the very limited amount of texts to be studied, but one group has rejected the whole notion of decypherment out of hand. Most, but not all, field archeologists (or "dirt" archeologists as they are sometimes known) take the position that all the art historians have done with their effort at translation is to produce the most boring and useless form of history, that is to say a list of kings and the events in their lives accompanied by dates that may or may not be propaganda. Commemorative monuments extolling the military prowess of a certain ruler may be nothing more than an ancient version of the Gulf War written by Saddam Hussein. So the dirt archeologists say "so what" to the epigraphers. When some concrete evidence is extracted that proves useful in the understanding of the daily lives of the Mayas related to subsistence and settlement patterns, trade relationships, social and political mechanisms, engineering, etc., then perhaps the archeologists will sit up and take notice.