<autobiographical_note date_range="1971-1972" theme="embarras de richesses">...I don't think my madcap theory is TOO mad. Unproven and undocumented, but not entirely implausible.
When, at the end of my first year, I had to choose options for Part II of my language degree, I bore in mind the amount of linguistic data there was relating to French (my main language at the time) and its documentation. I knew I wanted to study Romance Philology, and there were also several papers called 'History of <language-name>'. But French was a huge area, with many internally contradictory records; and the lecturer on the History of French had written the one book all students would have to read. And his reputation as a lecturer was not inviting.
So in 1972 I took up Portuguese, with a view to studying the History of Portuguese in my final year, thus avoiding a field of study that would have given me some insight into the origins of the es/est confusion – central to the madcap theory I mentioned last time. For further details of that theory – which is mine – read on.
The royal coat of arms of Great Britain bears the motto Dieu et mon droît (a reference to the divine right of kings). Google finds well over 200,000,000 hits for the rather feeble (not to say meaningless) translation 'God and my right'.
Somewhere (when I had reading rights in the old BM reading room) I found a French bible with the words Le Seigneur est ma justesse, which appears in the AV (no refs. today, my battery's about to die, as is my brain) as 'The Lord is my righteousness'.
Jean Bodin, the French mid-late-sixteenth century jurist, first introduced the idea of the divine right of kings to govern, basing his ideas on Roman Law. It was perhaps this authority that appears (uncited) in Bossuet's "Sermons choisis de Bossuet":
Image in Google Books
James VI of Scotland published his Basilikon Doron in Edinburgh in 1599, but he obviously wanted the English to understand his view of The Kingly Gift, as a London edition followed in 1603.
The Scots textbooks of the divine right of kings were written in 1597-98 by James VI of Scotland before his accession to the English throne. His Basilikon Doron, a manual on the powers of a king, was written to edify his four-year-old son Henry Frederick [sic but I imagine at least a colon is meant, if not a new sentence] king "acknowledgeth himself ordained for his people, having received from the god a burden of government, whereof he must be countable."
From Wikipedia on the Divine right of k'ings.
Cutting to the chase, let's imagine Dieu e[s]t mon droît was the translation in some French bible of the verse that appears in the AV as 'The lord is my righteousness'. The French-speaking Plantagenets would have met it. What better motto for Henry V (the first king of Great Britain to adopt the motto) to adopt as a statement of a newly defined right (Henry having picked it up from his forebear Richard I, who favoured it as a crusading battle cry [meaning, roughly, 'God's on my side'])?
Update 2014.06.0910.16:10 – Added this PS:
I must have dreamed my attribution of 'the Lord is my righteousness' to the Authorized Version: according to the searchable text provided by the University of Michigan, that exact phrase doesn't occur. A candidate for an alternative occurs at various places in the Book of Jeremiah, notably 23:6 – 'THE LORD OUR RIGHTEOUSNESS'.
Update 2014.06.09.16:55 – Added this PPS:
The quote in blue explains the bit about James's view of Basilikon Doron. He was the first major contributor to the doctrine of the divine right of kings. Other blue phrases are additions that fill in other bits of the argument.
Update 2014.06.15.18:55 – Fixed typos and added editorial gloss.
Update 2014.08.01.21.15 – Added 'translation' in maroon.
Update 2018.06.04.11:00 – Various typo fuxes and deleted old footer.