Piedras Negras is the modern name for an ancient, ruined city of the pre-Columbian Maya civilization located on the north bank of the Usumacinta River in the Petén department of northwestern Guatemala. The Mayan name for the city was Yo'k'ib'<nowiki/> () or Yokib. Piedras Negras was one of the most powerful of the Usumacinta ancient Maya urban centers. Occupation at Piedras Negras is known from the Late Preclassic period onward, based on dates retrieved from epigraphic information found on multiple stelae and altars at the site. considered a possible reference to a large (and now dry) sinkhole nearby. It may also have been a reference to its location as a prominent intermediary along the trade routes leading to the Tabasco floodplain. The second peak happened in the Late Classic period, around the second half of the 8th century, during which the maximum population of the principal settlement is estimated to have been around 2,600 people. At the same time, Piedras Negras was also the largest polity in the region, with a total population estimate of around 50,000.
thumb|The Emblem Glyph of Piedras Negras
Piedras Negras was an independent city-state for most of the Early and Late Classic periods, although it may have been allied with other adjacent states and may have paid-tribute to others, at times. It had an alliance with Yaxchilan, in what is now Chiapas state, Mexico, some 40 km up the Usumacinta River. Ceramics show the site was occupied from the mid-7th century BC to 850 AD. Its most impressive period of sculpture and architecture dated from about 608 through 810, although there is some evidence that Piedras Negras was already a city of some importance since 400 AD.
Panel 12 of Piedras Negras shows three neighboring rulers as captives of Ruler C. One of the captives might be the ninth king of Yaxchilan, Joy B'alam (also known as Knot-Eye Jaguar I), who continued to reign after the panel was made. As subservient rulers were often depicted as bound captives, even while continuing to rule their own kingdoms, the panel suggests that Piedras Negras may have established its authority over the middle Usumacinta drainage in about 9.4.0.0.0 (514 AD).
The artistry of the sculpture of the Late Classic period of Piedras Negras is considered particularly fine. The site has two ball courts and several plazas; there are vaulted palaces and temple pyramids, including one that is connected to one of the many caves on the site. Along the banks of the river is a large boulder with the emblem glyph of Yo’ki’b carved on it, facing skyward.
A unique feature of the monuments at Piedras Negras is the frequent occurrence of the so-called "artists' signatures". Individual artists have been identified by the use of recurring glyphs on stelae and other reliefs.
Ruler 7 (reigned 781-808?) of Piedras Negras was captured by K'inich Tatbu Skull IV of Yaxchilan. This event was recorded on the lintel 10 of Yaxchilan. Piedras Negras might have been abandoned within several years after this event.
Before the site was abandoned, some monuments were deliberately damaged, including images and glyphs of rulers being defaced, while other were left intact, suggesting a revolt or conquest by people literate in Maya writing.
Late Preclassic/Early Classic Rulers
Relatively little is known of the Late Preclassic/Early Classic rulers, but excavations of the West Group Plaza found masonry dating to the Early Classic; altar 1 is dedicated to Ruler A, dating to AD 297.
K'an Ahk I: AD 297- ?, induction Long Count Date: 8.13.0.0.0 Ancient Maya name is unknown, but some scholars believe his name to be Yah Ahk 1.
Ruler C: 514–53, induction Long Count Date: 9.4.0.0.0. It is not possible to fully ascertain whether limited occupation continued as no archaeological evidence has yet been unearthed for occupation continuing after AD 930.
Glyphs
Using the abundant number of stelae recovered from Piedras Negras, Tatiana Proskouriakoff revolutionized current understanding of Maya hieroglyphs. Proskouriakoff realized that stelae which depicted a person within a niche and the glyphic texts on them were in fact the long count recounting important events in the life of a ruler, such as their date of birth and accession to the throne.