Persepolis Fortification Tablets

The Persepolis Fortification Archive and Persepolis Treasury Archive are two groups of clay administrative archives — sets of records physically stored together - found in Persepolis dating to the Achaemenid Persian Empire. The discovery was made during legal excavations conducted by the archaeologists from the Oriental Institute of the University of Chicago in the 1930s. Hence they are named for their in situ findspot: Persepolis. The archaeological excavations at Persepolis for the Oriental Institute were initially directed by Ernst Herzfeld from 1931 to 1934 and carried on from 1934 until 1939 by Erich Schmidt.

While the political end of the Achaemenid Empire is symbolized by the burning of Persepolis by Alexander the Great (dated 330/329 BCE), the fall of Persepolis paradoxically contributed to the preservation of the Achaemenid administrative archives that might have been lost due to passage of time and natural and man-made causes. According to archaeological evidence, the partial burning of Persepolis did not affect the Persepolis Fortification Archive tablets, but may have caused the eventual collapse of the upper part of the northern Fortification wall that preserved the tablets until their recovery by the Oriental Institute's archaeologists.

Thousands of clay tablets, fragments and seal impressions in the Persepolis archives are a part of a single administrative system representing continuity of activity and flow of data over more than fifty consecutive years (509 to 457 BCE). These records can throw light on the geography, economy, and administration, as well as the religion and social conditions of the Persepolis region, the heartland of the Persian' Great Kings from Darius I the Great to Artaxerxes I.

...
Wikipedia