A perfect precedent would be the Persian-Zoroastrian King of Kings, Cyrus the Great. He ruled benignly and tolerantly, and his empire included a far greater variety of religions than in Britain today. He liberated many nations - Jews among them - from Babylonian captivity. The gods of all peoples under Cyrus's (and his heirs') rule were equally respected. He was anointed (and crowned) by the priests of all religions, according to their particular customs and rituals.
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