New Fantasy Setting Seeds.

[Astromancer]

The Elizabethans thought they were on the verge of a fuller understanding of magic. This attitude was maintained until the 1670s. The Restoration wanted to discredit magic. Although the Royal Society was founded by a practicing ritual magician it helped to associate "magic" with fanaticism and superstition, and to label "magic" a lower class thing.

Why not place a magical revolution in the time period when people were looking for one?

Both the 1590s and the 1640s are great periods to just add in magic. Assuming the breakthrough to a fuller understanding of magic takes place in England there would be a storm of spies coming to steal the secrets.

Read Phil Masters' Thaumutology:Age of Gold. The "rediscovery" of magic can be made to be something that comes from improved classical studies. Many people, including John Dee, thought and improved understanding of classical antiquity would lead to a return of magic.