By the grace of God

By the Grace of God is a phrase that has often been used in the titles of monarchs. For example, according to the "Royal Proclamation reciting the altered Style and Titles of the Crown" of May 29, 1953, Elizabeth II's full title is "Elizabeth II, by the Grace of God of the United Kingdom of Great Britain and Northern Ireland and of Her other Realms and Territories Queen, Head of the Commonwealth, Defender of the Faith".

The style was originally created to confirm the divine right of kings, that is, the endorsement of God to the monarch's reign; it is often abbreviated to "D.G." (Dei gratia, the phrase's Latin form). By custom, it is restricted to sovereign rulers; a vassal would never use the phrase, because he held his fief not by the grace of God, but by grant of a superior noble. Today, "by the grace of God" is included in the full titles and styles of the monarchs of Denmark, Liechtenstein, the Netherlands, and the United Kingdom, but not of Belgium, Luxembourg, Monaco, Norway, and Sweden.

(Spain's Constitution of 1978, in art. 56, para. 2, states that the title of the King of Spain is simply "King of Spain" (Rey de España), but that he also possesses the traditional titles of the Spanish Crown (podrá utilizar los demás que correspondan a la Corona). As a result, the King of Spain continues to be King "by the grace of God".)

In the Behistun Inscription high over the road connecting the capitals of Babylonia and Media, Babylon and Ecbatana, the Achaemenid Persian Darius I the Great had inscribed, in Old Persian, Akkadian, and the Elamite languages:

"King Darius says: By the grace of Ahura Mazda am I king; Ahura Mazda has granted me the kingdom."

Then he had the ledge chipped away that had supported the stonemasons, so that only Ahura Mazda could read the inscription.

"King by the grace of God" passed from the Persian monarchy to the heirs of Alexander, and was taken up by the later Roman emperors. And so it passed into Europe.

• The Behistun inscription.