Sasanian Drachm

The Sasanian drachm was the standard silver coin of the Sasanian Empire, which ruled Iran, Mesopotamia and neighbouring regions from the overthrow of the Parthians in 224 CE until the Arab conquest completed in 651. Each coin showed the reigning king wearing his personal crown on one side and a Zoroastrian fire altar on the other, with legends in Middle Persian written in the Pahlavi script.

Struck in very large numbers for more than four centuries, the drachm was the backbone of Sasanian state finance. It circulated along the trade routes of Central Asia, and its design was carried on by Arab governors after the conquest and imitated by neighbouring peoples to the east.

The founder of the dynasty, Ardashir I, took over the silver Parthian drachm, itself descended from the Greek drachma introduced into Iran after Alexander's conquest of the Achaemenid empire. Sasanian drachms weighed about 4 g of good silver for most of the dynasty's history. Early coins were relatively thick and compact; over time the flan became broader and thinner, and by the 5th and 6th centuries a typical drachm was a wide, thin disc around 3 cm across.

Silver dominated the Sasanian coinage. Gold dinars were struck in much smaller numbers, largely for ceremonial or prestige purposes, and copper coins for small change survive in limited quantity. Fractional silver pieces such as hemidrachms and obols were also produced.

The obverse shows the king's bust in profile. Every ruler adopted a distinctive crown, combining elements such as crenellations, wings, crescents and stars, usually topped by a globe of bound hair or fabric. Because the crowns differ from reign to reign, they are the main way numismatists attribute coins to individual kings. The surrounding legend gives the king's name and titles, typically describing him as a Mazda-worshipping divine ruler and king of kings of Iran; from Shapur I the title often adds "and non-Iran".

The reverse shows a fire altar, the central symbol of state Zoroastrianism. From the reign of Shapur I it is usually flanked by two attendants, and on some issues a bust appears in the flames. Later coins add rings of dots and stars and crescents in the outer margin.

From the later 5th century, reverses routinely carried an abbreviated mint name and the king's regnal year in Pahlavi. Dozens of mint signatures are known, though many of the abbreviations are still debated. This system allows coins to be dated to a specific year of a reign and makes the series an important source for Sasanian chronology. Output reached its peak under Khusrau II (590–628), whose drachms survive in enormous numbers.

Sasanian drachms travelled along the routes of long-distance trade into Central Asia and as far as China, where they have been found in tombs and hoards along the Silk Road. To the west, the empire's rival, Byzantium, relied on gold, and the gold solidus and silver drachm are often contrasted as the two great coinages of late antiquity.

In the east, successive rulers adapted the Sasanian model. Kushano-Sasanian governors struck coins in the former lands of the Kushans, and Hunnic groups produced imitations and countermarked drachms, a tradition described under Alchon Hun coinage.

After the conquest, Arab governors in Iran and Iraq continued to strike drachms in the Sasanian manner, most often copying the bust of Khusrau II, but adding short Arabic phrases such as "in the name of God" in the margin, and later the names of governors in Pahlavi. These Arab-Sasanian drachms ran in parallel with Arab-Byzantine coinage in the former Byzantine provinces.

The reform of AH 79 (698–699 CE) replaced them with the epigraphic silver dirham, which kept the broad, thin Sasanian flan while adopting the aniconic style of the gold Umayyad dinar. In this way the Sasanian drachm stands directly behind the later Abbasid dirham and the whole tradition of Islamic silver coinage.

• British Museum – Collection online
• American Numismatic Society
• Encyclopaedia Britannica – Sasanian dynasty