Blood River, short stream in KwaZulu-Natal province, South Africa, a tributary of the Buffalo (Mzinyathi) River. The river was the scene of a battle between the Zulu and the Voortrekker Boers on Dec. 16, 1838. The Zulu, under Dingane, were defeated by a Voortrekker commando force led by Andries Pretorius and suffered heavy losses caused by the Boers’ firepower. The river became known as Blood River after its water reddened with the blood of thousands of slain Zulu. (See Battle of Blood River.)