The Bard, John Martin
The link is to a zoomable version on the Google Art Project; there is a downloadable file on Wikimedia Commons. The original is in the Laing Art Gallery in Newcastle, UK, but their website is so poorly arranged I can’t even give you a link to the item.
Though 19th century British Romantic painter John Martin did paint scenes from Shakespeare, such as the meeting of the three witches with Macbeth, the Bard referenced here is from a poem of the same name by John Gray.
As Edward I conquers Wales in the 13th century, he encounters a bard who curses the king and his family line, predicts the return of Welsh self-rule, and makes his escape across a river and into the mountains beyond.
Martin has addressed the scene with his characteristic flair for scale and drama (modern concept artists take note — see my post on John Martin).
I love the scraggly nature of the trees — almost taking on the character of the rocks — and the wonderful multiplicity of planes of depth, particularly in the middle of the composition (as highlighted in my second detail crop, above).