The Darkening Age is a very readable book about a very depressing subject: the loss of knowledge, art and culture from the classical world when Christianity became mainstream. You often hear people saying that Christian monasteries preserved classical knowledge and literature, and it’s true — there are manuscripts which only survived because they were held in monasteries.
Unfortunately, as Catherine Nixey discusses at length, much more was destroyed by Christianity. Deliberately, purposefully, and with malice. Temples were torn down, books burned, inscriptions destroyed, etc, etc. If Christianity had truly been such a preserving force, we’d have a lot more than we do now, perhaps. Nixey goes through it step by step, the initial period of co-existence (and the fact that evidence suggests Christians were not persecuted nearly as much as they liked to think they were) and then the ramping up of hostilities, the sanctioned-and-encouraged utter destruction of “pagan” idols and temples, etc.
For such a heavy subject, it really is a very readable book, and I pretty much tore through it. It gets perhaps a bit repetitive, and other reviews are right to point out that there were other causes of the loss of texts, destructions of temples, etc.
The author is a journalist, rather than a historian, and the text is pretty much uninterrupted by footnotes/sourcing, so definitely be aware that it’s very much a popular history, and flavoured by opinion, rather than being an academic work. I found it an absorbing read!