The novel is the first in a trilogy[1] known as the Welsh Princes series set in medieval England, Wales and France that feature the Plantagenet kings.

Growing animosity between the English and Welsh results in Joanna having to act as a diplomatic intermediary between her husband and her father, and the situation deteriorates when Gruffydd is taken hostage by John and narrowly escapes execution.

Family disagreements lead Joanna into an affair with William de Braose, who is several years her junior and whom she has met earlier in the story when he was a hostage in Llewelyn's household.

"[3] Although set in the 12th and 13th centuries, narrative in her novels takes place in medieval sites that still exist and can be visited, including castles, churches and archeological areas.

[7] However, Rhian Piprell looks to Penman's treatment of Joan as a reminder that the idea of women wielding power and being influential is not a something unique to the modern world.

[9] The review in Library Journal cautions readers about the book's slow start, and confusing use of names, but concedes the novel is "involving" and "enjoyable".

"[7] New York Times Book Review was critical of list-like story telling which is too "brisk" and a tendency for tropes which slow the reader down too much.

For example, School Library Review claims Here Be Dragons "keeps readers enthralled," and that the novel is a "wonderful melange of historical fiction.

[17] Here Be Dragons, along with the subsequent novels Falls the Shadow and The Reckoning, inspired a sightseeing trail backed by the Tourism Partnership North Wales.