There’s a great little essay here by Brooke Palmieri on the JHI blog, which I’m reposting here mainly so that I don’t forget to go back and study in more detail. Excerpt:

No wonder Dee could argue so forcefully in General and rare memorials pertayning to the perfect arte of navigation (1577), and his other works, for a British Empire: there are books in his library to engineer such a feat. Alchemical works in theory provided instructions to make the gold to fund voyages to foreign lands. Books on astronomy, astrology, mathematics, cartography, and navigation make it possible for those ships to efficiently plan and complete the journey. Histories provide tough lessons and useful strategies about subjugating the locals: predominantly works about the Roman Empire, but also the Ottoman Empire (Francesco Sansovino’s Gl’annali turcheschi), and more recently works on trade with the East (João de Barros’s L’Asia) and the conquest of the New World (André Thevet’s La cosmographie universelle and Cosmographie de Levant). Cross-reference these with Matthew Paris’s Flores historiarum on King Arthur’s mythical dominion, and the justification for a particularly British Empire is given “historical” precedent. Finally, use magic to contact the angels and support human agency with divine right….