21 May 1884
King Dinizulu was the son of Chief Cetshwayo who reigned over Zululand, Natal (now kwaZulu-Natal) from 1872. Dinizulu was recognized as the legitimate heir and succeeded Cetshwayo in 1884. This was after Cetshwayo died, supposedly from poisoning on 8 February 1884, a year after he had returned to Zululand. Cetshwayo had been exiled to the Cape Colony by the British and was released in 1882 after a campaign run by the Anglican Bishop of Natal, John William Colenso. When Dinizulu took over the throne, Zululand was in a state of unrest following conflicts between the Zulus and British. This was precipitated when the British divided the Zulu Kingdom into 11 chiefdoms, some headed by chiefs who had defected to the British side. Dinizulu’s father, Cetshwayo had rivals from the chiefdom who opposed his supporters. This led to a civil war. Dinizulu’s relatives from the Zulu Royal House put him under the protection of their Boer allies in the border districts of the neighbouring South African Republic (the Transvaal). *Dinizulu is also spelt as Dinuzulu.
References

Akyeampong E.K., Gates H.R., Junior, Dictionary of African Biography, pp.53 & 205