Excerpts from Books and Wikipedia
"Admired because he was King Shaka, the man who transformed the unimportant Zulu clan into a powerful fighting nation of 250,000 people ruling large swaths of southern Africa; hated because of his love of power, destruction, and cruelty.… An accomplice created a diversion, and the two brothers stabbed their other brother to death.… The glory days were soon over for the Zulus. Shaka's successor, Dingane, challenged the Boers during the Great Trek but was defeated at Blood River in 1838, and his nephew Cetawayo, was decisively beaten by the British at Ulundi in 1879." [1001 Days]
"After Shaka's assassination by his half-brothers, Afrikaner migration north accelerated, notably in the 'Great Trek' starting in 1836, defeating and dispersing the Zulu and Nguni tribes in their path." [DK Timelines, p. 350]