The inspiration for the title "devaputra" may have come from rulers of which ancient civilization?

Chinese dynasties

During the first century BCE to the first century CE, the Kushanas, who held dominion over a vast kingdom spanning from Central Asia to northwest India, employed a compelling strategy to assert their elevated status - identifying with various deities. The Kushanas most prominently exemplify this approach through the use of inscriptions, textual traditions, and especially their coins and sculptures.

Colossal statues of Kushana rulers were discovered in a shrine located in Mat, near Mathura in Uttar Pradesh, as well as in another shrine in Afghanistan. These imposing sculptures offer valuable insights into the Kushanas' vision of kingship, which appears to portray them as godlike figures. Some historians have even suggested that the Kushanas deemed themselves divine beings. Moreover, numerous Kushana rulers adopted the title "devaputra," meaning "son of god," possibly influenced by the Chinese rulers who referred to themselves as "sons of heaven." This title further reinforced the connection between the Kushanas and divine authority.