The Achaemenid (or Persepolis[8]) clay tablets were loaned to the University of Chicago in 1937.[9] They were uncovered in Persepolis, Iran by Chicago archaeologists in 1933 and are legally the property of the National Museum of Iran and the Iran's Cultural Heritage Organization.[10][11] The artifacts were loaned based on the understanding that they would be returned to Iran.[8] The tablets, from Persepolis, the capital of the Achaemenid Empire, date to about 500 BCE.[8][9][10]