5924782 Lord Roberts and escort of Imperial Yeomanry entering Kroonstadt, South Africa, 1900 (b/w photo) by Underwood & Underwood (c.1881-1940); National Army Museum, London; (add.info.: ?Lord Roberts (3d to left) and Escort of Imperial Yeomanry entering Kroonstadt, Boer War, S.A.? Stereoscopic photograph, Boer War, 1900. After the setbacks sustained during ?Black Week? in December 1899 the British government realised it would need more men to defeat the Boers. It responded by raising the Imperial Yeomanry on 24 December 1899. Although based on the existing county yeomanry regiments, the new formations also contained a large contingent of volunteers. From a box of 89 stereoscopic cards entitled, ?South African War through the Stereoscope Pt 2 Vol 1\', published by Underwood and Underwood, and produced by Works and Sun Sculpture Studios, 1900 circa.); by National Army Museum .