A Walk In The Dark Ages (1988)
by Frank Delaney (-)
This book has an interesting premise: accompany an Irish monk of the seventh century on a pilgrimage to Constantinople, and describe the life of the Dark Ages through his eyes. It is not well done.
Delaney also wrote and narrated the BBC series The Celts, which also was a disappointment.
Delaney spends more effort describing his own modern journey than that of his monk, and the transitions back and forth are more jarring than illuminating.