April is National Poetry Month

We start off the month with a wee bit of mystery.
The fellow at left has a place in our history,
Might you be aware of this chap's claim to fame?
Well, prithee, please tell us then, what is his name?

You think you don't know him, but trust us, you do!
To help you we've even embedded a clue.
To leave us your answer, post a comment below.
If you're first to guess it, the whole world will know!