And Kennedy—was he really Julius Caesar, that most noble and greatest of Romans? Well, he did end up getting assassinated by his mates because he tolerated the Civil Rights Movement, and Cleopatra is there too in the form of Marilyn Monroe, the asp a CIA directed syringe and there’s even a Marc Antony floating around in there somewhere—Brother Bobbie. And Octavian?—the future Augustus Caesar?—surely that’s Lyndon Johnson if you believe the best and most probable of the conspiracy theories on the subject. There’s not much doubt that in 3963 AD, some future Shakespeare will have a field day creating an immortal legend from that lot.

…Where’s my serpent of the Nile?…
…My salad days,
When I was green in judgment…

…Age cannot wither her…
…He will to his Egyptian dish again…
…I am dying, Egypt, dying…

…Of the many thousand kisses the poor last I lay upon thy lips…
…those that do die of it do seldom or never recover…
…Dost thou not see my baby at my breast
That sucks the nurse asleep…
...Death, here is thy sting...

Drawn from Plutarch’s Life of Marc Antony and sticking closer to the facts than usual, Shakespeare’s only addition to the many other versions of Antony and Cleopatra that predate him is that he chose to considerably improve the character of the hero, making him a better man than history suggests he was. Indications are that Shakespeare went back to his primary source and rewrote the work from scratch, rather than enhancing any of the many other earlier versions as he more commonly did, but it was such a standard piece in those days (as it still is) that it cannot be called original in any sense.
  Here, too, is your chance to compare Shakespeare with the man who tried to emulate him in modern times—George Bernard Shaw. Shaw’s Caesar and Cleopatra might be regarded as a prequel, and it is very witty, very clever, nicely balanced and able to humanise these ancient characters better than most writings on such subjects. But it has attained none of the immortality of Shakespeare’s effort. Shaw’s attempt to upstage the master went the way of all imitators, and if anything, demonstrated just exactly how remarkable Shakespeare actually was. The man who was arguably the greatest playwright of both the 19th and 20th centuries just simply could not get to the pace.
Shakespeare Scoreboard:
Original plays 2. (MacBeth)(Henry IV Part One)
Plays ripped off from contemporaries 3. (Merchant from Marlowe’s Jew of Malta) (Hamlet from Kyd and Aeschylus) (Antony and Cleopatra—everywhere)