Majesty is an English word derived ultimately from the Latin maiestas, meaning greatness, and used as a style by many monarchs, usually kings or emperors. Where used, the style outranks [Royal] Highness. It has cognates in many other languages.Edit
Originally, during the Roman republic, the word maiestas was the legal term for the supreme status and dignity of the state, to be respected above everything else. This was crucially defined by the existence of a specific crime, called laesa maiestas, literally "Violated Majesty" (in English law Lese majesty, via the French Lèse-majesté), consisting of the violation of this supreme status. Various acts such as celebrating a party on a day of public mourning, contempt of the various rites of the state and disloyalty in word or act were punished as crimes against the majesty of the republic. However, later, under the Empire, it came to mean an offence against the dignity of the Emperor.