176 A. D. to 373 A. D. 9.0.0.0.0 to 9.10.0.0.0
During these ten katuns the great cities of the south make rapid strides towards grandeur. Pyramidal mounds are erected and temples built upon them. Public squares are laid out and in these are set up stelæ and altars. The leading early cities are Palenque, Tikal, and Copan, where the dated monuments and temples mark rapid progress in the arts of sculpture and architecture while the subject matter of inscriptions reveals growing ability in astronomy and mathematics. Low angular relief characterizes stone sculptures and the profile presentation of the human figure is now handled more skilfully than front view.
Middle Period
373 A. D. to 471 A. D. 9.10.0.0.0 to 9.15.0.0.0
Some of the most beautiful monuments of the Mayas belong to this middle period. While archaism does not entirely disappear there is freshness, purity of style, and straightforwardness of presentation about the sculpture of this age. Flamboyancy is not apparent. At Copan the Great Mound was practically carried to completion during this period, an enormous undertaking which absorbed so much energy that few stelæ were set up. The best series of monuments from the middle period are seen at Naranjo and Piedras Negras.
Great Period
471 A. D. to 629 A. D. 9.15.0.0.0 to 10.3.0.0.0
Many cities flourished in the culminating years of Mayan civilization. In addition to those already mentioned Quirigua, Ixkun, Seibal, Nakum, Cancuen, Yaxchilan, Toniná, and Kobá were important centers while a complete list of the sites with dated monuments would show many more names. The territorial extension reaches from northern Yucatan to the Guatemalan highlands and from southern Vera Cruz to central Honduras. Art passes through interesting changes with tendencies towards flamboyancy. Architecture makes great advances: rooms become wider, walls thinner and forms more refined and pleasing. The calculations deal more and more with complicated astronomical subjects and dates belong less and less in the category of contemporary history. The first age of Mayan civilization, called the First Empire, comes to an end with Katun 3 of Cycle 10, a date registered at Uaxactun which, strangely enough, also boasts the earliest stela with a contemporary date. It is indicated that Uaxactun was occupied for 561 years while the range of dates at Tikal is 394 years. Abandonment of all the sites of the First Empire took place within something like fifty years. What caused this collapse? Civil war? Social decadence? Failure of food supply? Or perhaps some overwhelming epidemic? There is good reason for believing that the sudden appearance of yellow fever may have had a part in the catastrophe. References in the Chronicles to the First Empire are very brief and do not help us find the answer to this mystery.
Transition Period
629 A. D. to 964 A. D. 10.3.0.0.0 to 11.0.0.0.0