THAT the two Kingdoms of Scotland and England shall upon the first day of May next ensuing the date hereof, and for ever after, be united into One Kingdom by the Name of GREAT BRITAIN; And that the Ensigns Armorial of the said United Kingdom be such as Her Majesty shall appoint,, and the Crosses of St Andrew and St George be conjoined, in such manner as Her Majesty shall think fit, and used in all Flags, Banners, Standards and Ensigns, both at Sea and Land.
While separate kingdoms, England and Scotland could in theory have had separated through separate laws of succession, and indeed the coming succession crisis brought that danger perilously close. Scotland, entirely dependent on England for trade and security, had no voice in its councils, and was open to mistreatment in any falling-out between the two, as had recently occurred over trade and the succession.
They new kingdom flew one flag – the issue of the flag of Great Britain may have been considered settled: the Union Flag had been established for a hundred years, but it was not. In Scotland a slightly different pattern for that flag had come into use (we do not know when) and was amongst the designs presented to the Garter King of Arms to choose one. In the event he chose the familiar pattern as the colours of the new kingdom: the St Andrew flag of Scotland, with a fimbrated red cross of St George given house-room upon it.