One criticism of historical fiction is that we novelists make stuff up. Yes, we do. We call it fiction for a reason.
That criticism assumes that history tells us everything. It doesn’t. Not by a long shot. While I am grateful for primary sources, their authors did not hesitate to omit events that made the boss look bad or twist the truth to make the boss look good.
I am fascinated by the history of the early Middle Ages, the time period for my novels, but no primary source will tell you what it was like for an ordinary pagan family in Saxony to watch a sacred monument be destroyed. Nor will it say what it was like for a woman and her children to lose the freedom they took for granted.
See my guest post on Royalty Free Fiction for more about why I decided that the best way to learn about an ordinary early medieval family was to make one up.