For 10 points, name this leader in the war for Dutch Independence, whose grandson of the same name ascended to the English throne during the Glorious Revolution.
This man called himself "George Certain" in coded letters addressed to "Lambert Certain." His Apology dated his ancestry back to Otto II. His first territorial acquisition, done entirely without his knowledge, occurred after a ferryman vastly overestimated the size of de la Mark's forces; that acquisition was commemorated in a poem celebrating the stealing of the spectacles of the Duke of Alva. This man gave letters of marque to the Sea Beggars, which allowed them to raid Spanish ships. He was shot by Balthasar Gerard, a Jesuit priest. For 10 points, name this leader in the war for Dutch Independence, whose grandson of the same name ascended to the English throne during the Glorious Revolution.
This man called himself "George Certain" in coded letters addressed to "Lambert Certain."
{William the Silent} [or {William} of {Nassau}-{Dillenberg}; prompt on {William} of {Orange}]