Spying was a profession 400 years ago due to the intense rivalry of France and England. Vast sums and amounts of time were spent on various schemes. Probably for revenge for losing western Europe in the 100 years war. Religion seems to have been mostly a cover for plunder and stealing treasure. France remained mostly Catholic, however the religious turnover in England created interesting dynamics.

The proprietor of Maryland landed the title Baron Baltimore through friendship with the spymaster to Queen Elizabeth, "whom Calvert had met during an extended trip to the European mainland between 1601 and 1603".

"He also held the title of Earl of Salisbury in 1605 and Lord High Treasurer in 1608, making him the most powerful man at the royal court."

The Calvert family lost the Maryland estate after the armed insurrection of 1689, however the Crown returned the estate to the Calvert family in 1715 "after Charles Calvert, 5th Baron Baltimore, declared in public that he was a Protestant."

The final "23rd Governor of Restored Proprietary Government" Sir Robert Eden, 1st Baronet, was the great great grandfather of Prime Minister Anthony Eden.

https://en.wikipedia.org/wiki/George_Calvert,_1st_Baron_Balt...

https://en.wikipedia.org/wiki/Province_of_Maryland

https://en.wikipedia.org/wiki/Secret_Treaty_of_Dover