As the last great Iranian ruler before the advent of Islam, the Sasanian dynasty (224-642 AD) is best remembered for its distinctive cultural expressions and the longevity of its rule. With an immense territory stretching from Transcaucasia to the Indus Valley, Sasanians were particularly engaged in intense trade and exchange, of which, sealstones and bullae are an interesting reflection.
Bullae (from the latin Bulla-ae) are clay or bitumen impression of seals used as voucher that were usually attached to documents or – in fewer instances- parcels (or the strings used to bound them) and showed the identity of the author or witness of the document , or the owner of the merchandise. While a number of clay bullae from the Sasanian era have been discovered at various Sasanian sites including Takht-e Suleiman and Qasr-e Abu Nasr, many seal impressions have been recovered in Transoxiana, bearing inscriptions in Sogdian. Bullae are important historical documents in that they provide valuable information on Sasanian onomastics, personal names, government offices and religious positions. Their wealth of information is particular poignant, when considering that relatively little material evidence has so far come to light from the Sasanian period, besides the vestiges of architectural religious complexes.

The bulla, used as a voucher, was originally attached to strings that once wrapped the document or letter. Then it was often broken and discarded, once the document was to be opened. Yet collections of bullae, found in deposits are known to have been indeed stored in archives. The impressions of Sasanian seals, preserved on clay bullae suggest that the seals functioned as validation of documents as as guarantees of exchanged goods and services both in an administrative context and in private society. Sasanian bullae such as the one here illustrated have a convex face and a relatively flat back with, sometimes, traces of perforations or grooves left the strings that attached the bulla to the sealed object.
Scholars seem to agree on the typology and purpose of bullae in both civil and domestic environments; administrative ones for instance, were generally un-iconic and exclusively epigraphic, giving the names of administrative provinces and the titles of offices such as those of finance and justice, both posts held by the Zoroastrian clergy. On the other hand, those bullae used for royals and important functionaries generally bear the owner’s bust accompanied by an inscription giving the his name and title. Private seals and impressions, distinguished by a single motif sometimes accompanied by an inscription, provide a rich variety of iconographic patterns, largely reflecting the contemporary cultural and religious traditions of Iran, though only indirectly explained by the inscriptions accompany them.

The bulla here illustrated portrays an argali ram within a beaded medallion, his neck surrounded by fluttering ribbons suspended behind. Such imagery is comparable to several textile depictions (like the fragment in the Metropolitan Museum of Art, New York) datable to the Sasanian period and encountered throughout Central Asia, especially in Sogdiana.
Unlike the Greek and Roman examples, Sasanian bullae of high quality or functional importance usually bear inscriptions, providing a proper name, often followed by a patronymic and occasionally with a pious or auspicious phrase such as ‘be generous’ or ‘trust in god’. The glyptic scripts used for palhavi, the middle Persian language of the Sasanians, are based on the lapidary script, found on Sasanian reliefs of the 3rd century, and the cursive script used in chancery and for commercial activities. Other scripts found on bullae include Parthian, Sogdian, Aramaic, Syriac and Arabic.

Reference:
Azarpay, G. “Bullae from the Palhavi archive at the University of California, Berkeley”, Eran ud Aneran, Studies Presented to Boris Ilich Marshak, Buenos Aires, 200
Bivar, A.D.H, Catalogue of the Western Asiatic Stamp Seals in the British Museum, Stamp Seals II, The Sassanian Dynasty, London 1969.

Brunner C.J., Sasanian Seals in the Metropolitan Museum of Art, The Metropolitan Museum of Art, New York, 1978.

Gignoux, P. “ A propos de quelques inscriptions et bulles sassanides”, Histoire et culte de l’Asie Central preislamique, CNRS, Paris, 1991: 66-67.

R.N. Frye, "Sasanian clay sealings in the collection of Mohsen Foroughi," Iranica Antiqua, VIII, 1968, p. 118-132, pl. XXIV-XXXI. R. N. Frye, "Sasanian clay sealings in the Baghdad Museum," Sumer, 26, 1970, p. 237-240. - pl. XXXI, fig.3
Ph. Gignoux - R. Gyselen, Bulles et sceaux sassanides de diverses collections, [Cahiers de Studia Iranica, n° 4] Paris, Association pour l'Avancement des études iraniennes, 1987.

We are grateful to Dr Rika Gyselen, CNRS, Paris, for her help in identifying the bulla.