Stela and altars in the Great Plaza at Copan

Stelae and altars were erected to mark important political & calendrical events

"In every civilization of the ancient world, there are art works and monuments that stand out among their fellows as objects of special character. The great portrait sculptures that stand in silent rows down the center of the Great Plaza of Copan created one of these special places. They constitute one of the great masterpieces of the Maya legacy.

Although the artists who made them did not sign their works and leave us their names, the patron of these great works did. He was Waxaklahun-Ubah-K'awil (whose name glyph translates as 18-Rabbit), the thirteenth king of the Copan dynasty."

Linda Schele & Peter Mathews, The Code of Kings: The Language of Seven Sacred Maya Temples and Tombs, p. 133