This chapter examines two linked engagements during the Colesberg campaign of early 1900: the skirmish at Agtertang Station on 3 January and the Battle of Slingerfontein on 9–10 January. British forces under Major General John French sought to secure railway lines and dominate the surrounding high ground, while Boer commandos under Generals Schoeman, Piet de Wet, and later Koos de la Rey attempted to halt their advance. The chapter highlights the role of mounted troops, particularly the newly arrived 1st New Zealand Contingent, whose reconnaissance, outpost duties, and defensive actions contributed significantly to British operations. Their stand on 15 January at what became known as New Zealand Hill—alongside the Yorkshire Regiment—proved decisive, repelling a determined Boer attack with minimal losses. The narrative also includes biographical notes on individual soldiers such as Trooper Alister Hugh Matheson and Private George Bradford, the first New Zealander to die in the Anglo-Boer War. Overall, the chapter situates these actions within the broader strategic contest for control of northern Cape Colony and the eventual British consolidation around Colesberg.