Research Contribution 2

Confirming the Date AD 998 for El Osario, Chichen Itza

Bruce Love and Greg Reddick

In 1999 Daniel Graña-Behrens, Christian Prager, and Elisabeth Wagner published an article in Mexicon that concluded, in effect, that Eric Thompson was correct in 1937 when he stated that the south-east pillar on top of El Osario[1] (Figure 1) at Chichen Itza bears the date AD 998. It is now eighteen years since Graña-Behrens et al.’s article appeared, during which time we have heard some colleagues question this date, mainly because it is so late and so far outside the cluster of other dates from the site, which lie mostly in the second half of the ninth century (for summaries of Chichen dates see Boot 2005: Table 4.4; Volta and Braswell 2014: Table 13.1).

My beautiful picture
Figure 1. El Osario (3C1 in the Carnegie Institution of Washington system of nomenclature), east stairway (Photo by Bruce Love, June 6, 2014).

The pillar with the inscription that is the subject of this blog is one of four standing within the temple walls at the top of the pyramid (Figure 2). In 2014 Love re-photographed the pillar, presented here with Peter Mathews’s drawing of the same (Figure 3a, b), and took close-ups of the text (Figure 4a) using numerous light angles.[2] From these photographs, Love made a new drawing of the text (Figure 4d) and compared them with drawings by Peter Mathews (Figure 4b) and Graña-Behrens, Christian Prager, and Elizabeth Wagner (Figure 4c).

Figure 2
Figure 2. Plan view of El Osario temple on top of building (Maudslay 1974 [1889-1902], Vol. 3: Plate XXIV [annotated]).
Figure 3a-b
Figure 3a-b. East side of SE Pillar in El Osario temple: a, photo by Bruce Love, June 6, 2014; b, drawing by Peter Mathews (Lincoln 1986:162, Fig. 5.1).
Figure 4a-d
Figure 4 a-d. Text on east side of SE Pillar: a, photo by Bruce Love, June 6, 2014; b, drawing by Peter Mathews, made from field drawing and photos (Lincoln 1986:162, Fig. 5.1); c, drawing by Daniel Graña-Behrens, Christian Prager, and Elizabeth Wagner (Graña-Behrens et al. 1999:Fig.2) based on photographs of casts made by Carnegie Institution of Washington, rubbings by Conrad Kratz, also part of the Carnegie Institution Chichen Itza Project, and rubbings by Merle Greene Roberstson; d, drawing by Bruce Love, made from 25 close-up photographs, each with a different light angle, taken at night, June 6, 2014.

Reviewing and comparing these drawings, it seems evident that the text does indeed begin with the calendar round 2 Ajaw 18 Mol and that F2-F6 can be translated as “10 K’an [the] day, 2 Sotz’, eleventh tun [of K’atun] 2 Ajaw.”

These dates were examined for their possibilities by Greg Reddick using his Xoc Maya Calendar program (Reddick 2014) with the result that the only year in which these two calendar rounds fall in the eleventh tun of a K’atun 2 Ajaw is the year AD 998.

2 Ajaw 18 Mol;; May 6, AD 998[3]
10 K’an 2 Sotz’;; Jan. 30, AD 998

The second date is extremely solid if the glyphs are being read correctly, as there is no other date in Maya history that meets the parameters of 10 K’an 2 Sotz in the eleventh tun of K’atun 2 Ajaw, and the fact that the first calendar round also falls in the eleventh tun of K’atun 2 Ajaw doubly confirms its correctness.

Addressing the question of “if the glyphs are being read correctly,” the syntax of the final phrase, F2 to F6, is typical of Tun-Ajaw dates at Chichen Itza as expounded by Thompson (1937), examples of which can be found on some seventeen monuments listed by him (ibid.:8).

Although AD 998 is 90 years later that the last Long Count date in the Classic Maya lowlands, which is on Monument 101 at Tonina (Martin and Grube 2008:189), and, as already mentioned, falls outside the range of other Chichen dates, we would say that rather than being anomalous, it fits comfortably within the “Toltec” or “Mexican” or “International Style” period to which El Osario belongs. Intriguingly, there is a cluster of dates from the Dresden Codex Serpent Numbers pages that also encompasses the El Osario dates.[4]

Table 1
Table 1. A group of Long Counts and their Gregorian equivalents reached by Serpent Numbers in Dresden Codex (pp 61-62, Thompson 1972:80) and the two dates from El Osario, arranged in order from oldest to youngest.

In a recent archaeological synthesis of the site, based in part on new excavations in the gran nivelación or great central platform, Geoffrey Braswell states that “most of the structures currently visible in the northern portion of the site were built during the interval 900/950 to 1050.” He sees Chichen Itza thriving “throughout the tenth and well into the eleventh century” (Braswell 2012:21; see also Braswell and Peniche 2012). This view agrees with that of Peter Schmidt who sees Chichen Itza as an “important economic and political center at least sometime through the eleventh century” (Schmidt 2007:194).

More recently, William Ringle has reviewed Braswell’s material and, although offering counter arguments regarding much in Braswell’s article, in essence concurs with Braswell’s dates stating that Modified Florescent Chichen Itza (the architecture that includes El Osario), while for the most part a tenth century phenomenon, had constructions that “may well have continued into the eleventh century” (Ringle 2017:15-16).

Obviously this short article is not the place to enter into the grand debate surrounding the Toltecs and Chichen Itza; the purpose of this blog is to report that the two calendar rounds and the Tun-Ajaw date falling within the year AD 998 have been confirmed independently from new photographs and drawings. Students of Maya history may use this date with confidence.


Boot, Erik
2005 Continuity and Change in Text and Image at Chichen Itzá, Yucatán, Mexico. CNWS Publications, Leiden.

Braswell, Geoffrey
2012 Reinterpreting the Past of the Northern Maya Lowlands. In The Ancient Maya of Mexico: Interpreting the Past of the Northern Maya Lowlands, edited by Geoffrey Braswell, pp. 1-40. Acumen Publishing, Durham, UK

Braswell, Geoffrey and Nancy Peniche May
2012 Excavations of the Great Platform of Chichen Itza. In The Ancient Maya of Mexico: Interpreting the Past of the Northern Maya Lowlands, edited by Geoffrey Braswell, pp. 230-262. Acumen Publishing, Durham, UK.

Graña-Behrens, Daniel, Christian Prager, and Elisabeth Wagner
1999 The Hieroglyphic Inscription of the “High Priest’s Grave” at Chichen Itzá, Yucatán, Mexico. Mexicon Vol. XXI, June 1999, pp. 61-66.

Lincoln, Charles E.
1986 Chronology of Chichen Itza. In Late Lowland Maya Civilization: Classic to Postclassic, edited by Jeremy A. Sabloff and E. Wyllys Andrews V, pp.141-196. School of American Research Advanced Seminar Series, Douglas W. Schwartz, general editor, University of New Mexico Press, Albuquerque.

Martin, Simon, and Nikolai Grube
2008 Chronicle of the Maya Kings and Queens: Deciphering the Dynasties of the Ancient Maya. 2nd ed. Thames and Hudson, London.

Maudslay, Alfred Percival
1974 [1889-1902] Biologia Centrali-Americana: or, Contributions to the Knowledge of the Fauna and Flora of Mexico and Central America, Vol. 3, edited by F. Ducane Godman and Osbert Salvin. R. H. Porter and Dulau & Co., London. 1974 facsimile edition prepared and introduction written by Francis Robicsek. Milpatron Publishing Corp., New York.

Reddick, Greg
2014 Xoc Maya Calendar, computer software, version 3.0, Xoc Software. Retrieved from

Ringle, William M.
2017 Debating Chichen Itza. Ancient Mesoamerica

Schmidt, Peter
2007 Birds, Ceramics, and Cacao: New Excavations at Chichen Itza, Yucatan. In Twin Tollans: Chichen Itza, Tula, and the Epiclassic to Early Postclassic Mesoamerican World, edited by Jeff K. Kowalski and Cynthia Kristan-Graham, pp. 151-204. Dumbarton Oaks Research Library and Collection, Washington D.C.

Thompson, J. Eric S.
1937 A New Method of Deciphering Yucatecan Dates with Special Reference to Chichen Itza. Contributions to American Archaeology, No. 22, Publication 483, Carnegie Institution of Washington, Washington, D.C.

1972 A Commentary on the Dresden Codex: A Maya Hieroglyphic Book. American Philosophical Society, Philadelphia.

Volta, Beniamino, and Geoffrey E. Braswell
2014 Alternative Narratives and Missing Data: Refining the Chronology of Chichen Itza. In The Maya and Their Central American Neighbors: Settlement Patterns, Architecture, Hieroglyphic Texts, and Ceramics, edited by Geoffrey E. Braswell, pp. 356–402. Oxon, Routledge.

[1] Peter Schmidt, long-time director of Proyecto Arqueológico Chichén Itzá, rejects the name “High Priest’s Grave” because the only burial found there was a secondary burial found in the fill within the building’s central shaft and was not of high status (Peter Schmidt personal communication 2009).

[2] Photography by Bruce Love was authorized by Centro INAH Yucatán May 27, 2014 Oficio No. 401.F(22)90.2014/CIY-VU-572. He is grateful to Antrop. Eduardo Lopez Calzada, Delegado of Centro INAH Yucatán for expediting his permit, and to Arqlgo. Marcos Antonio Ramírez, Director of the Zona Arqueológica de Chichén Itzá, for facilitating his visit and making him welcome. He also thanks INAH project illustrator Guillermo Couoh for helping with the photography.

[3] All western dates are Gregorian using the 584283 correlation.

[4]  There is also a cluster of three dates from the late 8th century on these Serpent Numbers pages (Dresden 60-61)

Suggested citation: Love, Bruce and Greg Reddick. “Confirming the Date AD 998 for El Osario, Chichen Itza” Contributions to Mesoamerican Studies, December 22, 2017.

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