 The site was later excavated by Ernst Herzfeld, and was again investigated in part by Giorgio Gullini in a short expedition of 1960.Initially, Herzfeld tentatively dated the palace complex to the 1st century CE, that is, to the Arsacid period (248 BCE-224 CE).Herzfeld later revised his estimate to a later date and today the Sassanid period (224-651 CE) is usually considered to be more likely.