But which was before that known as a Petrarchan sonnet since it originated with Petrarch...

As someone who has read a lot of Shakespeare (no, let me finish...) I can compare it a little to having seen a comic artist's work...you know it's him even though you would have a little trouble telling someone else how you know...Shakespeare's works say Shakespeare in the same way that JB's say JB...so the Tempest is Shakespeare to me in the same way that Doom Patrol, say, is JB to you...I had to study (not had to, it was an unmitigated JOY, darling (!)) Elizabethan and Jacobean literature for my degree and it really is not hard to differentiate Shakespeare from Webster or Jonson or Marlowe...someone asks you is that Kirby or a copy and you can tell most (I'd say all) times,

This doesn't answer the question I myself raised, but I think it's interesting.

Your airmiles may differ 

One of my favorite links of the chain is that De Vere's widow apparently left, in her will, 100 pounds to Will Shaksper of Stratford, "our silent friend".

Also, when interviewed some ten years after his death, Shaksper's daughter had no idea her father was supposed to be the greatest playwright in the land. (She wouldn't have been able to read the plays, anyway. Altho he supposedly authored stories featuring some of the strongest female characters in literature, all well eduacted, Shaksper did not allow his own daughters to be schooled, even enough to learn to read and write.)

The first time the name turns up as an attributation, by the way, it is spelled "Shake-spear". In theatrical "code" of the time, a hyphenated name in which the second part is lower case was an indication of a false or made-up name. Usually, this was for characters, as when Ben Jonson named an incompetent physician "Dr. Fill-grave" in one of his plays. Still, let us never forget the De Vere crest...:

For fans of Shakespeare:

Written work (one hell of a big book!):

Plays on CD