Proposed flag designs for a “Great Britain” in the early 1600s, when James became king of both still-independent countries, as covered in BBC Radio 4’s The Flag That Failed, part of the Shakespeare’s Restless World season.
Handily, there’s a transcript available:
Looking at our flag designs, you can see the intractable politics of union being played out in graphic form. All the designs stumble on the one key problem facing James’s project: how do you combine two kingdoms, but allow each to retain equal status? Crudely put, which national cross gets to be on top, St George or St Andrew’s, and does size matter?
If you’ve never seen a Union Jack, it is surprisingly difficult to come up with an even-handed solution to this particular problem.
The programme page has a zoomable image of the designs. As it was, in 1606 a recognisable Union Flag that has evolved into the current design was used, although England and Scotland were not formally joined as a single country until 1707, after the failure of the Darien Scheme (as covered by CP Grey in one of his informative videos).