difference between highness and majesty
Highness is a courtesy title used for members of the Royal family but not the sovereign monarch. Princes and Princesses are often Royal Highness. This is mostly about differences in rank. TL,DR : Majesty is used for kings, queens, emperors and empresses which are the highest ranks in a country. Highness is used for princes and princesses. Today, this is a common concept, even if there are different protocols. The Emperor of Japan is addressed as His Majesty and not His Imperial Majesty.