It was, for example, made into the official emblem of the Russian state by Ivan III (r: 1462-1505) in the late fifteenth century. In the Byzantine Empire the eagle represented the power of the emperor, while its two heads represented the emperor’s authority of secular and religious matters respectively. It should be noted that this emblem was also copied on both secular and religious items that had nothing to do with the royal courts.
Metropolitan Museum of Art online catalogue (retrieved 7th May 2016).
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