Indo-Parthian kingdom

For a few generations around the start of the Common Era, a family of Parthian origin ruled a loose realm stretching from eastern Iran across Afghanistan and into the Indus valley and Punjab. Modern scholars call it the Indo-Parthian kingdom; Sanskrit texts knew its people as Pahlavas, and because its kings may have belonged to the noble House of Suren, some authors, and our maps, call it the Suren Kingdom. Its best-known ruler, Gondophares I, is remembered both from coins and from the Christian legend of Saint Thomas.

The kingdom grew out of Drangiana, the region also known as Sakastan or Seistan, which Parthian governors had held since Mithridates II subdued the Saka there. Gondophares I seems to have been one of these governors who threw off allegiance to the Parthian king. The usual date given for the break is 19 or 20 CE, but his reign is hard to fix: the numismatist Robert Senior argues that his eastern conquests may have come as early as 20–10 BCE, while other scholars place his rule between about 19 and 46 CE.

Gondophares pushed east into lands held by the Indo-Scythians and the last Indo-Greeks. At his height he ruled Arachosia, Seistan, Sindh, Punjab and the Kabul valley, though apparently not much beyond eastern Punjab. He took the Parthian style of King of Kings, appropriate for a realm in which many lesser rulers, among them Saka satraps and the Apracaraja princes, kept their thrones by accepting his supremacy. Taxila is thought to have been one of the Indo-Parthian capitals.

After Gondophares I died, his successors divided the realm. Several later kings used his name as a title, among them Sarpedones, Orthagnes and Sases, while his nephew Abdagases ruled in Punjab. None regained the founder's authority, and from about the mid-first century CE the Indian provinces were gradually absorbed by the Kushan ruler Kujula Kadphises.

No inscription or legend records an Indo-Parthian king supporting Buddhism, unlike the Indo-Greeks and Saka before them, and their coins avoid the Buddhist symbols those rulers used. Being of Iranian origin, they are thought to have kept to Zoroastrianism, and a temple at Jandial near Taxila is often read as a fire temple; coins of Gondophares I with the Hindu god Shiva are also known. Even so, Gandharan Buddhist art flourished in their territory. Sculptures from Sirkap show figures in Parthian dress of crossover jackets, baggy trousers and headbands, and the great monastery of Takht-i-Bahi near Mardan, now a World Heritage Site, is associated with them.

The apocryphal Acts of Thomas tell how the apostle Thomas came to the court of an Indian king called Gudnaphar, usually identified with a Gondophares. Whether the story has any historical basis is uncertain, and if it does the king could have been a later bearer of the name. The Greek writer Philostratus says the sage Apollonius of Tyana visited Taxila around 46 CE and met a Greek-speaking king named Phraotes.

Indo-Parthian rulers held on in Sakastan and Turan, in today's Baluchistan, after losing India. These remnants submitted to the Sasanian founder Ardashir I around 224–230 CE, and a related local line, the Paratarajas, came under Sasanian influence around 262. Parthian Buddhist monks such as An Shigao, active in China in the second century, carried the faith eastward along the Silk Road.

Our maps draw the Suren Kingdom in -1, 100, 200, 300 and 400. Its kings had submitted to the Sasanian Empire by about 230 CE, so the 300 and 400 outlines extend beyond the kingdom's actual life. Its neighbours include the Indo-Scythian Kingdom, the Kushan Empire and the Parthian Empire from which it broke away.