The royal "we" (Pluralis Majestatis) is the first-person plural pronoun when used by an important person to refer to himself or herself. Its best known usage is by a monarch such as a king, queen, or pope. It reflects the fact that when a monarch speaks he or she speaks both in his own name and in the name of his function, office or status.
Most famous quote is Queen Victoria's "we are not amused", (referring to her own lack of amusement).
From climate change / Al Gore, to rugby, to PD as an (auto)immune condition, to English personal pronouns, we sure are covering a lot of ground with our typically incisive wit and drive
Neil.