Cetewayo was born a son of Zulu king Umpanda who was a brother of Zulu king Shaka. In 1856 he defeated and killed in battle his younger brother, Umpanda's favorite, and became the effective ruler of Zulu tribe. However, he did not really ascend to the throne because his father was still alive.
His other brother Umtonga was still a potential rival and he knew it. In 1861 Umtonga fled to Boers' side of the border and Cetewayo had to make deals with Boers to get him back. In 1865 Umtonga did the same thing and apparently made Cetewayo think that Umtonga could try replace him the similar way his father had replaced his predecessor Dingaan.
Umpanda died in 1873 and Cetewayo took full power. He expanded his army against and readopted many methods of Shaka. He also equipped his impi's with muskets. He banished European missionaries from his land. He might have incensed Kaffirs and Sikukuni to rebel against Boers in Transvaal.
In 1878 Sir Henry Bartle Frere, British Commissioner for South Africa, begun to demand reparations for border infractions. They mainly angered Cetewayo who kept his calm until Frere demanded that he should effectively disband his army. His refusal lead to Zulu War in 1879. After first defeats British eventually begun to gain victories. After Cetewayo's capital Ulundi was captured and torched on July 4 he was deposed and exiled to London.
By 1882 differences between two Zulu factions – pro-Cetewayo Usutus and three rival chiefs - had erupted into a blood feuds and civil war. In 1883, the British tried to restore Cetewayo to rule at least part of his previous territory but the attempt failed. Chief Usibepu started a war – with the aid of Boer cavalry mercenaries – and on July 22, 1883 he attacked Cetewayo's new kraal in Ulundi. Cetewayo was wounded but escaped. He died in February 1884