John Dee

Coined "British Empire," charted Elizabeth I's northern voyages, and spent his last 25 years taking dictation from angels.

Dee was the most learned man in Tudor England: he taught Euclidean geometry to navigators, advised on the calendar reform Britain refused, plotted the polar routes for Frobisher and Davis, and produced the first English translation of Euclid's Elements (his preface is still reprinted). From 1582 onward he partnered with Edward Kelley, a convicted forger who claimed to scry angelic messages in a polished obsidian disc, and recorded thousands of pages of an "Enochian" angelic language. The geometry and navigation were nation-building infrastructure. The Enochian séances were a long con and a marriage-swap.