I read this story decades ago, in a F&SF collection.
Longish novelette or maybe a shortish novella, I don't remember. I don't think there was actual any element of fantasy, just alternate history (well, I suppose things did not happen exactly as told in the story).
I don't remember much. It describes Shakespeare on his death-bed, thinking about whom to mention in his will, and reminiscing. For some reason he feels a huge guilt which is not quite clear, but IIRC, some people were killed in the past. Whom, and by whom, I completely forgot. I am almost sure noone was killed by Shakespeare's hand. But guilt was there.
I think there are some flashbacks, also. Other characters are Anne Hathaway and their daughters.
I have been thinking about the story. I am not quite sure, but I think the man on his death-bed worrying about his will is not the real Shakespeare. Though I am pretty sure he did not kill anyone with his own hands, he feels guilty about being in some way responsible of the death of the real Shakespeare and then pretending to be him, coming back to Stratford after a long absence and hoping noone would be able to tell. IIRC, Anne Hathaway immediately knew about the substitution, but kept silent.