A little Duke (on titles of direct address)

Ah, to every rule there are exceptions. That's what really makes research interesting. On the subject of use of titles of direct address. I believe all the titles - Duke, Earl, Baron, etc. have the same issue : is the form [title] [firstname] correct in period (i.e. Duke Jocko)? A quick search of Shakespeare shows that he mostly uses the form (at least in 3rd person address, but I see no reason it wouldn't be the same for direct address) [firstname], Duke of [placename], as I think is usually correct (i.e. Jocko, Duke of Flatbush), but there is this example from Henry VI:

GLOUCESTER: Brave peers of England, pillars of the state,To you Duke Humphrey must unload his grief,...
CARDINAL: So, there goes our protector in a rage. 'Tis known to you he is mine enemy, Nay, more, an enemy unto you all, And no great friend, I fear me, to the king. Consider, lords, he is the next of blood, And heir apparent to the English crown: Had Henry got an empire by his marriage, And all the wealthy kingdoms of the west, There's reason he should be displeased at it. Look to it, lords! let not his smoothing words Bewitch your hearts; be wise and circumspect. What though the common people favour him, Calling him 'Humphrey, the good Duke of Gloucester, 'Clapping their hands, and crying with loud voice, 'Jesu maintain your royal excellence! 'With 'God preserve the good Duke Humphrey!' I fear me, lords, for all this flattering gloss, He will be found a dangerous protector.

So, I'd say let's hit those books, folks, and see what other example we find.

And interestingly, Robert Greene, in his famous "A Groatsworth of Wit", which first comments on Shakespeare - usually the connection is keyed off of the phrase "A tiger's heart wrapp'd in a player's hide", alluding to the phrase in Henry VI, but I had never seen mentioned before (from A Groatsworth of Wit - 1592:[http://darkwing.uoregon.edu/~rbear/greene1.html]"

Roberto perceiuing no remedie, thought best to respect of his present necessitie, to trie his wit, & went with him willingly: who lodgd him at the Townes end in a house of retayle, where what happened our Poet, you shall after heare. There, by conuersing with bad company, he grew A malo in peius, falling from one vice to another: and so hauing found a vaine to finger crowns, he grew cranker than Lucanio, who by this time began to droope, being thus dealt with by Lami[l]ia. Shee hauing bewitched him with hir enticing wiles, caused him to consume in lesse than two yeeres that infinite treasure gathered by his father with so many a poore ma[n]s curse. His lands sold, his iewels pawnd, his money wasted, he was casseerd by Lamilia,that had coosened him of all. Then walkt he like one of Duke Humfreys Squires, in a thread-bare cloake, his hose drawne out with his heeles, his shooes vnseamed, least his feete should sweate with heat: now (as witlesse as hee was) hee remembred his Fathers words, his vnkindnes to his brother, his carelesnes of himselfe. In this sorrow hee sate downe on pennilesse bench; where when Opus and Vsus told himby the chimes in his stomacke it was time to fall vnto meate, he was faine with the Camelion to feed vpon the aire, & make patience his best repast."

So, Greene obviously knew his Shakespeare and used the phrase as Shakespeare did - "Duke Humfrey".