England/Great Britain: Royal Styles: 1604-1707

With the accession of the House of Stuarts to the throne of England (1603), the personal union emerged, but the kingdoms of England and Scotland remained separate polities. Despite a short-lived union in the form of the Commonwealth, the countries did not merge into a single nation until 1/12 May 1707, when the Acts of Union, passed by the respective Parliaments in 1706 and 1707, went into effect. King James I (James VI) was the first British monarch, who began using the style "King of Great Britain" to avoid more complicated "king of England and Scotland" and to emphasize the unity of the two kingdoms. A royal proclamation of 20/30 Oct 1604, which was published on 24 Oct/3 Nov 1604 for England and proclaimed for Scotland on 15/25 Nov 1604, provided an official status for the style "king of Great Britain":

... We doe by these Presents, by force of our Kingly Power and Prerogative, assume to Our selfe by the cleerenesse of our Right, The Name and Stile of KING OF GREAT BRITTAINE, FRANCE, AND IRELAND, DEFENDER OF THE FAITH, &c. as followeth in Our just and lawfull Stile, And doe hereby publish, promulge and declare the same, to the ende that in all Proclamations, Missives forreine, and Domesticall, Treaties, Leagues, Dedicatories, Impressions, and in all other cases of like nature, the same may be used and observed.

At the same time the proclamation restricted the application of the new style emphasizing its non-statutory use:

And for that Wee doe not Innovate or assume to Us any new thing, but declare that which is and hath bene evident to all; Our will and pleasure is, That in such Appellations or Nominations, as shall be hereafter made by force of these presents, the same shall bee expressed in such and the same maner and forme, and after such computation, as if we had assumed and declared the same the first day of our Raigne of our Realme of England; Forbearing onely for the present that any thing herein conteined doe extend to any Legall proceeding, Instrument, or Assurance, untill further Order be taken in that behalfe.

The opinion of the English judges prevented James I from getting this style adopted by Parliament for "Legall proceeding, Instrument, or Assurance". In Scotland the newly proclaimed title was accepted by Parliament, but the subsequent history both in England and in Scotland is extremely complicated all the way to the Act of Union 1707.

Non-statutory use of the new style is found on king's Great Seals and coins. The style "king of Great Britain" (MAGNAE BRITANNIAE REX) appears on all Great Seals instead of the more formally correct "king of England and Scotland" (ANGLIAE SCOTIAE REX) in 1625-1627, 1640-1649, 1660-1689, 1695-1707. Coins of James I and his successors used MAGNAE BRITANNIAE REX.