Kushan script

The unknown Kushan script (écriture inconnue in French, neizvestnoe pis’mo in Russian, both meaning unknown lettering ) is a partially deciphered writing system and abugida, written from right to left, used to record a Middle Iranian language related to Bactrian. It was used in parts of Central Asia between 600-200 BCE (depending on the age of the Issyk inscription) and 700 CE, including the Kushan Empire, associated with the nomads of the Eurasian Steppe in ancient Bactria. It was discovered by archaeologists in the 1950s. Textual remnants consist of cave wall carvings and painted ceramics. Most of what was written was probably recorded on palm leaves or birch bark which had decomposed. It was used by the Kushan administration along with Greek and Kharosthi scripts. The script contained less than 30 signs, and likely around 25. It is possibly an Imperial Aramaic-derived script, modified with diacritics.

Several decipherment attempts were made, mostly focusing on the oldest instance of the script, the Issyk inscription, without success. The partial decipherment was announced on 1 March 2023 by a team at the University of Cologne, when the consonant values of 15 signs, 2 ligatures, and 4 vowel diacritics had been determined. The corpus is primarily short inscriptions that originate from the territory of today's Tajikistan, Afghanistan, and Uzbekistan. A significant discovery that led to progress on decipherment was a bilingual carving found in the Almosi Gorge in northwestern Tajikistan, which included a section in the Bactrian language and ancient Greek writing. It was used in addition to the trilingual Gandhari-Bactrian-Kushan inscription discovered in the 1960s at Dašt-i Nāwur, Mount Qarabayu in Afghanistan, as the name of emperor Vima Takto and his title King of Kings appears in both texts.

Vladimir Liwshits originally pointed out that the Issyk inscription bears a resemblance to later, similarly undeciphered inscriptions from the Kushan Empire, dated to the 2nd-3rd centuries CE. This includes texts found at Dašt-i Nāwur, Surkh Kotal, Al-Khanoum, and seven other short inscriptions. He and Edvard Rtveladze suggested calling it the Saka script, because it apparently appeared in the time of the Saka and was used by ones that joined the Yuezhi to establish the Kushan Empire. Harmatta proposed a decipherement in 1999 based on this hypothesis.

However, due to some deviations, Gérard Fussman hypothesised that they could be attributed to several writing systems. The Sakan hypothesis was also met with skepticism due to the possibility that the Issyk inscription originates from Bactria via trade or loot. As of 2014, the majority of experts considered the script to be undeciphered.

Some researchers have claimed similarities with the Orkhon runes and tried to read them as inscriptions in Old Turkic. However, due to the attempts all widely varying in their attempted decipherments, they have not been considered successful. Liwshits claimed that this is because they shared a common origin in the Imperial Aramaic script.

A 2023 analyses by Bonmann et al., identified the Kushan script with a new sub-branch of the Eastern Iranian languages, particularly a language "situated in between Bactrian-, Sogdian-, Saka- and Old Steppe Iranian". They also argue "since it is not an ‘unknown script’ anymore, we suggest to call the writing system ‘(Issyk-)Kushan script’ from now on".