The Leiden Plaque: a Maya jade records a royal accession in 320

The plaque, a slab of pale green jadeite about 22 cm long, was pierced to be worn as a pendant, probably from a belt. On the front a lord in an elaborate headdress clasps a double-headed ceremonial bar across his chest, while a bound captive lies behind his feet. On the back fifteen glyphs, with traces of cinnabar, give the date 8.14.3.1.12 1 Ebʼ 0 Yaxkʼin — 14 or 16 September 320 in the Julian calendar (15 or 17 September in the proleptic Gregorian calendar used by Mayanists) — and record the accession of a ruler. In 1938 Frances and Sylvanus Morley argued that it was almost certainly made at Tikal: only there do stelae show the captive lying behind the feet of the main figure, as on the plaque. They also took its date for the earliest contemporary date in Maya inscriptions; the earlier Tikal Stela 29 (292) was found only in 1959. The name in the text was long read as “Moon Zero Bird” and taken for an early king of Tikal; more recent studies read it as a place name and treat the link with Tikal as possible but not proven.

The plaque was found by chance in 1864, when the Dutch engineer S. A. van Braam was cutting a canal for a timber company near present-day Puerto Barrios, in the swampy lowlands of the lower Motagua valley. It lay in a mound with potsherds and copper bells — a treasure kept for centuries before it was buried, far from any major Maya city. Taken to the Netherlands the same year, it is kept in the National Museum of Ethnology in Leiden; in 2006 it was chosen as one of the national symbols of Guatemala and appears on the one-quetzal banknote.