In Dark Earth, sisters Isla and Blue attempt to claim protection from a warlord under the laws of sixth century England, while also hiding the fact that they've broken those laws. This part of British history was a time of transition, and the laws of the land were no exception to that. Starting in the fifth century, Germanic peoples immigrated to Britain. In the past it was believed they belonged to three tribes: the Angles, the Saxons and the Jutes — hence the term Anglo-Saxon. However, modern research has shown that these people were from a variety of groups, and much less unified than previously thought.

When they arrived, they found a land already populated by a diverse mix of native Britons, displaced Romans and former Roman allies. There is ongoing debate as to how many people actually migrated to the British Isles and how they interacted with the people already there. Gildas, a monk writing in the sixth century, says that conflict arose between these groups. According ...