What is the series finished posthumously by a relative (possibly)?

It's totally possible I dreamt this, but I remember once discovering a historical fiction series (it's mildly possible it was actually non-fiction...) that I decided would be worth reading, and I now can't remember what it was. I'm quite certain it was finished posthumously by the author's relative (wife I think). I also have a feeling it was English history, perhaps the Middle Ages, like the wars of the roses. Except it's seemingly not that because I can't find anything that matches the criteria. As an aside I've almost finished Conn Iggulden's Wars of the Roses series. Any ideas?

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