Note: Four novels Three Zulu novels are in the Allan Quatermain series at ISFDB, numbers 1, 3, and 13, following the fictional chronology (as of August 2019). The Chronology table at Wikipedia: "Allan Quatermain" covers all works in that and two overlapping series, ISFDB series Ayesha and Zulu Nation. Wikipedia lists Nada the Lily in its "Chronology of Haggard's Quatermain and Ayesha stories", as set about 1800 BCE. The same section of Wikipedia fictional character article "Allan Quatermain" (above) covers the Zulu trilogy thus:

In the Zulu trilogy, Marie (1912), Child of Storm (1913), and Finished (1917), Quatermain becomes ensnared in the vengeance of Zikali, the dwarf wizard known as "The-thing-that-should-never-have-been-born" and "Opener-of-Roads". Zikali plots and finally achieves the overthrow of the Zulu royal House of Senzangakona, founded by Shaka and ending under Cetewayo (Cetshwayo kaMpande) (Haggard's questionable spelling of Zulu names is used in the first instance).

Wikipedia calls Child of Storm "the second in a trilogy by Haggard involving the collapse of the Zulu kingdom and featuring the dwarf Zikali." Zulu witch-doctor Zikali and Zulu chieftain Umslopogaas also appear in She and Allan, or Allan Quatermain #10 at ISFDB, which is not set in Zululand.