Grrr.... that bit when you're reading a history book you've been looking forward to for a while, enjoying it, thinking you're learning stuff, and then it blithely makes a statement you know to be utter bollocks, meaning you can't trust any of the rest of it either, and wonder whether to continue...
In this case, Stephen Talty's Empire Of Blue Water, a bio of the life and exploits of Henry Morgan, which on p.36 tells us "Privateering [as opposed to piracy] was invented by Henry VIII" - Bzzzt! Wrong answer. The earliest survivng letter of Marque and Reprisal/Commission to a privateer issued in England was issued by John in 1205. Henry IV issued four surviving ones, in 1400, 1404, 1405, and 1411. Henry V issued a surviving one against Genoa in 1413, and *then* Henry VIII finally put one out against France and Scotland in 1543.
It doesn't survive, but we know Edward III issued at least one set somewhere around 1344-5-ish as well
(My SCA persona is a Privateer, you see, so Ive done the research on Letters of Marque and Reprisal, and also I've written stuff about these periods)