The origins of Kujula Kadphises are quite obscure, and he is usually believed to be a descendant of the Kushan ruler Heraios, or possibly identical with him. However, Kujula shares his name with some of the last Indo-Scythian rulers, such as Liaka Kusulaka, or his son Patika Kusulaka, which might suggest some family connection.
Chinese accounts
There are few contemporaneous accounts of Kujula Kadphises; since none of these texts are by Kushan authors, their accuracy and the motives of the authors may be questionable. For example, the rise of Kujula Kadphises is portrayed, in a later Chinese historical chronicle, Hou Hanshu, as the result of a bloody civil war.
he prince of Guishuang, named Qiujiuque , attacked and exterminated the four other princes . He established himself as king, and his dynasty was called that of the Guishuang King. He invaded Anxi , and took the Gaofu region. He also defeated the whole of the kingdoms of Puda and Jibin . Qiujiuque was more than 80 years old when he died.
In the process of their expansion eastward, Kujula Kadphises and his son Vima Takto seem to have displaced the Indo-Parthian kingdom, established in northwestern India by the Parthian Gondophares since around 20 CE:
His son, Yangaozhen , became king in his place. He defeated Tianzhu and installed Generals to supervise and lead it. The Yuezhi then became extremely rich. All the kingdoms call the Guishuang king, but the Han call them by their original name, Da Yuezhi .
The invasion of the Indo-Parthian kingdom led by Kujula Kadphises is thought to have occurred some time after 45 CE, during the reign of Gondophares's successors: Abdagases and Sases.
The connection of Kujula with other Kushan rulers is described in the Rabatak inscription, discovered in Rbatak, Afghanistan some years ago, which was written by Kanishka. Kanishka makes the list of the kings who ruled up to his time: Kujula Kadphises as his great-grandfather, Vima Taktu as his grandfather, Vima Kadphises as his father, and himself Kanishka:
And he gave orders to make images of the same, of these gods who are written herein, and he gave orders to make for these kings: for King Kujula Kadphises great grandfather, and for King Vima Taktu grandfather, and for King Vima Kadphises father, and for himself, King Kanishka.
Coinage
Most of Kujula's coins were Hellenic or Roman in inspiration. Some coins used the portrait, name and title of the Indo-Greek king Hermaeus on the obverse, indicating Kujula's wish to relate himself to the Indo-Greek king. Since the Kushans and their predecessors the Yuezhi were conversant with the Greek language and Greek coinage, the adoption of Hermaeus cannot have been accidental: it either expressed a filiation of Kujula Kadphises to Hermaeus by alliance, or simply a wish to show himself as heir to the Indo-Greek tradition and prestige, possibly to accommodate Greek populations. These coins bear the name of Kujula Kadphises in Kharoṣṭhī, with representations of the Greek demi-god Heracles on the back, and titles presenting Kujula as a "ruler", and a probable Buddhist. Later coins, possibly posthumous, did describe Kujula as "Maharajasa", or "Great King".
The Greek script on the coins of Kujula is barbarized. For example, ΣΤΗΡΟΣΣΥ on his Hermaeus coins is thought to be a deformation of ΣΩΤΗΡΟΣ, the traditional title of Hermaeus on his coins. The Greek word for "king" is written ΒΑϹΙΛΕΩΣ, with both a lunate sigma and a normal sigma in the same word. The Kushans also added one character to the Greek script: it is the letter Ϸ, corresponding to the sound "Sh", as in "Kushan".
"Buddha" coins
Some coins of Kujula also represent a cross-legged seated figure, formerly said to be one of the first known representations of the Buddha on a coin. Unfortunately, Whitehead's attribution of this coin to Kujula, and the claim that the seated figure on the obverse represents the Buddha, is now known to be incorrect. The correct attribution of this coin is to the Kushan king Huvishka, who was Kujula's great-great-grandson. The obverse shows Huvishka seated on a couch. The first known coins carrying a representation of the Buddha were issued by Kujula's Great-grandson Kanishka I.
Roman-style coins
Some fewer coins of Kujula Kadphises also adopted a Roman style, with effigies closely resembling Caesar Augustus, although all the legends were then associated with Kujula himself. Such influences are linked to exchanges with the Roman Empire around that date.
