Finished
H. Rider Haggard
(Independently published, April 25, 2020)
While this can be read on its own, it's the final book in the Zulu trilogy within the Allan Quatermain series (to get the full impact, read Marie followed by Child of Storm and then Finished). This one is set during the Anglo-Zulu War of 1879, and as with the others, features some real-life people as characters along with the fictional folks like Allan.