The Pacific coast of Chiapas [1] and present-day Guatemala is believed by archaeologists to be the cradle of Maya civilization. It was there that the earliest proto-Maya tribes—from which the great pre-Colombian Maya societies eventually grew, and today’s Maya are descended—first formed small fixed settlements, practicing basic agriculture and producing surprisingly sophisticated pottery and tools. They slowly spread south into Central America and north as far as the Gulf coast of the Yucatán Peninsula, splintering into dozens of distinct ethnic and language groups.
Present-day Chiapas came to be home to various groups, many of which are still present today: Tzotziles and Tzeltales cultivated the highlands, Choles inhabited the northern jungles, Tojolabales lived in the plains in today’s Lakes Region, and the Mam people lived in the coastal regions. The western portion of the state was originally occupied by Zoques (who may be more closely related to Olmecs than Mayas), who were later conquered by Chiapa war tribes, probably arriving from Central Mexico.
The Chiapas were the dominant power at the time of first Spanish contact, and so the state bears their name.
Links:
[1] http://www.moon.com/destinations/chiapas