Forged by Iron is based on Olaf Trygvason’s saga, which appears in Snorri Sturluson’s Heimskringla, among other sources. Fortunately for modern storytellers, the sagas tend to focus on the big picture, which leaves plenty of room for literary license, and Schumacher’s retelling modifies some aspects of the story for narrative purposes.
Trying to understand the Vikings takes some patience and careful research. They built homes of wood and turf, and their clothes were mostly wool and linen, so much of the physical evidence of their travels and lifestyle has been ravaged by natural processes. Viking societies depended heavily on oral communication, and many of the texts we have today were written down a century or more after the Viking Age. Determining how the information may have changed over that time is tricky business, and we can only guess how many stories were completely lost over the years. One story that has survived is the Christianization of Iceland. But did the Icelanders turn to Christianity out of fear of volcanic eruptions, as some researchers have suggested?