Andries Pretorius chose his ground carefully. Where the Ncome curved, an eight-meter drop fell away into a deep hippo pool, guarding two sides of his position. To the front lay open veld with no cover at all. Into this bend he drew sixty-four ox-wagons, chaining them wheel to wheel into a laager, and wedged movable barriers into the gaps. At two corners he set artillery, including a six-pound naval carronade he had hauled from the Cape and nicknamed Grietjie. His commando numbered roughly 464 men. Across the plain waited an army estimated at twenty-five to thirty thousand. The night before, a thick mist settled over the wagons while the sky above stayed clear. The Boers hung lanterns on their whip-stocks and waited for dawn.

When the light came, a Trekker recalled that "all of Zululand sat there." The Zulu charged in waves, and a Zulu eyewitness remembered that the first charge was mown down like grass by the muskets. The short stabbing spear was a fearsome weapon at close range, but the open ground gave the warriors no way to close it without crossing a killing field swept by grapeshot and gunfire. Four times they came on. Four times the volleys broke them, while the lulls between gave the Boers time to reload. After two hours, Pretorius sent horsemen out from the laager to shatter what remained of the formations. The Zulu held for a while, then scattered. Pretorius's war secretary Jan Bantjes counted about three thousand dead. On the Trekker side, three men were wounded. None were killed.

The man who commanded the Zulu that day was Ndlela kaSompisi, a veteran who had served under Shaka and risen to become Dingane's prime minister. The defeat was not his alone to bear, but bear it he did. Two years later, after the Battle of Maqongqe, Dingane had Ndlela slowly strangled with a cowhide thong, condemned for treason because he had spared and protected the king's rival half-brother, Mpande. Dambusa, Dingane's other general, had already been executed by Mpande and Pretorius. The river that ran red had set in motion a Zulu civil war. When Mpande finally took the throne, the kingdom that had crushed the British forty years later at Isandlwana had already begun to splinter from within.

For most of the twentieth century, this was Afrikaner sacred ground. The day was called the Day of the Vow, commemorating a covenant the commando had sworn to God before the battle, and Afrikaner nationalists read divine favor into the outcome. A granite ox-wagon was raised here in 1947, and a full bronze laager of sixty-four wagons followed in 1971. But across the Ncome stands a second memorial, opened in 1998, that honors the Zulu dead. In 1994 the holiday was renamed the Day of Reconciliation. At the 1998 inauguration, Zulu leader Mangosuthu Buthelezi apologized to the Afrikaner nation for the killing of Piet Retief, then named the suffering of the Zulu under apartheid, and called the date "a new covenant" binding all South Africans to a shared country. Today both banks remember. They simply remember different dead.