The royal we, or majestic plural (pluralis majestatis), is the use of a plural pronoun (or corresponding plural-inflected verb forms) to refer to a single person who is a monarch. The more general word for the use of a we, us, or our to refer to oneself is nosism.
Speakers employing the royal we refer to themselves using a grammatical number other than the singular (i.e., in plural or dual form). For example, in his manifesto confirming the abdication of Grand Duke Constantine Pavlovich, Emperor Alexander I begins: "By the Grace of God, We, Alexander I, Emperor and Autocrat of All the Russias ...."
The royal we is commonly employed by a person of high office, such as a monarch, earl or pope. It is also used in certain formal contexts by bishops and university rectors. William Longchamp is credited with its introduction to England in the late 12th century, following the practice of the Chancery of Apostolic Briefs.
In the public situations in which it is used, the monarch or other dignitary is typically speaking not only in their own personal capacity but also in an official capacity as leader of a nation or institution. In the grammar of several languages, plural forms tend to be perceived as deferential and more polite than singular forms. This grammatical feature is common in languages that have the T-V distinction. English used to have this feature but lost it over time, largely by the end of the 17th century.
In diplomatic letters, such as letters of credence, it is customary for monarchs to use the singular first-person (I, me, my) when writing to other monarchs, while the majestic plural is used in royal letters to a president of a republic.
In Commonwealth realms, the sovereign discharges their commissions to ranked military officers in the capacity of we. Many official documents published in the name of the monarch are also presented with royal we, such as letters patent, proclamation, etc.
Popes have historically used the we as part of their formal speech, for example as used in Notre charge apostolique, Mit brennender Sorge, and Non abbiamo bisogno. Since Pope John Paul II, however, the royal we has been dropped by popes in public speech, although formal documents may have retained it. Recent important papal documents still use the majestic plural in the original Latin but are given with the singular I in their official English translations.[full ]
Several prominent epithets of the Bible describe the Jewish God in plural terms: Elohim, Adonai, and El Shaddai. Many Christian scholars, including the post-apostolic leaders and Augustine of Hippo, have seen the use of the plural and grammatically singular verb forms as support for the doctrine of the Trinity. The earliest known use of this poetic device is somewhere in the 4th century AD, during the Byzantine period.
In Imperial China and every monarchy within its cultural orbit (including Japan, Korea, and Vietnam), the majestic imperial pronoun was expressed by the character zhèn (?) (Old Chinese: *lr?m?). This was in fact the former Chinese first-person singular pronoun (that is, 'I'). However, following his unification of China, the emperor Shi Huangdi arrogated it entirely for his personal use. Previously, in the Chinese cultural sphere, the use of the first-person pronoun in formal courtly language was already uncommon, with the nobility using the self-deprecating term gu?rén ('lonely one') for self-reference, while their subjects referred to themselves as chén ? ('subject', original meaning 'servant' or 'slave'), with an indirect deferential reference like zúxià ('below [your] foot'), or by employing a deferential epithet (such as the adjective yú (?), 'foolish'). While these practice did not affect the non-Chinese countries as much since their variants of zhèn (?) and other terms were generally imported loanwords, the practice of polite avoidance of pronouns nevertheless spread throughout East Asia. . This still persists, except in China, where, following the May Fourth Movement and the Communist Party victory in the Chinese Civil War, the use of the first-person pronoun ? w?, which dates to the Shang dynasty oracle inscriptions as a plural possessive pronoun, is common. 
In Hindustani and other Indo-Aryan languages, the majestic plural is a common way for elder speakers to refer to themselves, and also for persons of higher social rank to refer to themselves. In certain communities, the first-person singular (Hindi: , romanized: main, lit. 'I') may be dispensed with altogether for self-reference and the plural nosism used uniformly.
In these letters the plural "We" and "Our" are employed instead of "I" and "My," and the letters terminate thus: "Your Good Friend." This form is used mainly for Royal letters to Presidents of Republics.