"Anonymous" is the Holocaust denial of literature placed before you in movie format. It has long been rumored--and frequently debunked--that one Edward de Vere, 17th Earl of Oxford wrote all of Shakespeare's works in anonymity because writing was heresy or worse among England's titled. The good earl, it is postulated in this movie, was a lot like modern writers in that he wound up in poverty. Problem with him, though, was that he began as a fabulously wealthy titled gent.
You get the usual British crown intrigue (which grows more tiresome with each depiction) with some truly nasty people in positions of power and even the writers--Shakespeare, Christopher Marlowe and Ben Johnson, have little to recommend them. The British huddled masses share just one commonality with the Republican-like power brokers: bad teeth. And they are monumentally bad.
The story is actually interesting if you look at it strictly as a work of fiction. Shakespeare, for example, is portrayed as an illiterate buffoon of an actor who falls into deVere's plays quite by accident and has no hesitation about putting his name on them and taking the bows, the fame and the money that come with all that. Keeping the secret that he didn't really write them becomes increasingly difficult, especially with a throne change looming and intrigue at its height. Words, says de Vere, are power and they can trump swords. They don't here, but you get a an inkling of his point.
The recommendation here is to suspend disbelief, see the movie and enjoy it for what it is: a respite from convention, a visual triumph and a movie acted and directed quite well. One aspect that may throw you: this is not a linear story and it jumps all over the place in a most confusing manner.
If you want to see Shakespeare, rent "Shakespeare in Love."