The Kushana period between the first and third
centuries was a time that witnessed immense
cultural, economic, political and geographical
growth. It was an era marked with extensive wealth
and growth of arts. Their rise to power marks an
important period in the history of central Asia. They
enjoyed close ties with countries such as China and Greece. Trade between various countries also
brought forth a lot of changes in their lives. Religious
changes included the expansion of the Buddhist faith. Hinduism, Iranian religious beliefs and Zoroastrianism
When excavations were carried out at Taxila, they showed that the Kadphises preceded the Kanishka group of kings as coins of the Kadphises group, but not of Kanishka, Huvishka, etc. Early Kushana coins were decorated with inscriptions like ‘the Great King, the King of Kings, the Son of Heaven, the Kushana’.
Dated to the first year of Kanishka's reign in 127 CE, the casket was discovered in a deposit chamber under Kanishka's stupa, during the archeological excavations in 1908-1909 at Shah-ji-Dheri on the outskirts of Peshawar. The original is today at the Peshawar Museum and an old replica is in the British Museum. Rarities inside the casket are said to have included three bone fragments of the Buddha.
The inscription on the casket is signed by the maker, a Greek artist named Agesilas, who oversaw work at Kanishka's stupas (caitya), confirming the direct involvement of Greeks with Buddhist artworks [the inscription reads in part, "The servant Agisalaos, the superintendent of works at the vihara of Kanishka ..."].
The attribution of the casket to Kanishka has been recently disputed, on stylistic grounds [the casket may instead be attributable to Kanishka's successor Huvishka].
The Kushana era helped in defining the chronological framework of the Kushana dynasty through its inscriptions. These inscriptions date from years 1-23 of Kanishka, years 24 and 28 of Vasishka, years 28-60 of Huvishka and years 67-98 of Vasudeva. The beginning of the Kanishka era can be dated back to A.D. 134, which is a century before the second Kushana era.