Ambush at Sannah’s Post: A Devastating British Defeat in the Boer War Boer Commandant-General Christiaan de Wet laid a clever trap for an unsuspecting British garrison in the Orange Free State. Here's What You Need to Know: Despite his unprepossessing appearance, De Wet had a keen mind for strategy and a quick eye for tactics. During the infamous Black Week of December 1899, the proud British Army suffered three consecutive bloody defeats in southern Africa. In each of the clashes, Boer citizen-soldiers, called burghers, held fast to their defensive positions and repelled poorly executed attacks by the supposedly better-trained British forces. The shocking victories at Stormberg, Magersfontein, and Colenso lifted Boer morale while crushing British hopes for a quick, decisive victory against the outgunned and outnumbered enemy.