Exeter Book
The Exeter Book is a book written ca. 10th Century by an anonymous writer who apparently was inspired by the Wanderer. The origins of this book, or where it can be found is unknown. It has at least one entry made by an anonymous writer, inspired by someone he or she calls "the Wanderer". Seeing as the Dark Wanderer travelled the Anoroch desert around the 13th century, it's unknown who this "Wanderer" could be.
Likely, it's just a misprint from Blizzard, as the text indicates that the Wanderer is indeed Diablo, talking about his years under Tristram and looking for his Three Brothers.
Excerpt
Each dawn, I rise alone, mired in ancient sorrows. Wretched and deprived of my native land. I have had my mind bound with fetter. For many years, I lay hidden in the concealment of the earth, buried deep in stone. From there, I went, abject and winter-grieving, over the surface of the waves. I sought the prison of my noble kinsman. Sorrow is a cruel companion to one who can afford few friends, and the path of exile attends this mournful spirit.
And so this world, every day, is crumbling and falling. The rulers lie dead, deprived of revelry, bands of warriors lie fallen proud by the wall. War destroyed some, carried them away; a sorrowful man hid one deep within a grave. Thus the creator of men laid waste this dwelling-place, until the old works of giants stood vacant, without the noise of their inhabitants.
So said Wanderer, set apart in secret meditations.
Inspired by The Wanderer (Anonymous),
from the Exeter Book, ca. 10th Century.