Here they are!
The Battle of Blood River, 16 December 1838.
Besieged on all sides, before the battle, the Voortrekkers took a Vow, in return for God's help in obtaining a positive outcome that they would honour this day, as a holy day of God, forever. Giving Thanks!
The odds was not in their favor.
During the battle a group of about 470 Voortrekkers defeated a force of almost 10 000. Three of the Voortrekkers was wounded and almost 3000 Zulu warriors died in battle.
PS: Piet Retief and his men was killed on the 6th February 1838, by Dingane, after the signing of the treaty. (This included 100 men, Retief was left to watch the massacre, which included his son. He was left to the end.