Devaraja

[Vanbakkam Vijayaraghavan]

What is the vedic precedents conceptually and ritually of the concept
of 'devaraja' which came to be a premier medievel Hindu mode of politico-
religious authority in India and more so in south east asia? It is also
said by some historians that the ultimate conquest of one king by another
king used to be carrying away (not desecrating) the royal image /deity
symbolising the annexation of that principality?

Is this devaraja concept an innovation of medievel India/ South east asia
(i.e. post 3rd C Ad) without precedents or ritual support?