Rubuta ci gaba ga wannan sakin layi - A ranar 9 ga Disamba, 1899, De Wet ya sami sakon waya daga Shugaban Jiha, M.T. Steyn, yana sanar da shi cewa an nada shi janar mai yaƙi kuma ya ci gaba zuwa iyakar yamma. Ya sami Janar Piet Cronjé a matsayin kwamandan sojojin Boer da ke Magersfontein, kudu da Kimberley, yayin da Ingilishi ke Kogin Modder. De Wet zai zama mataimakin Cronje. An fara ci gaban Burtaniya a ranar 11 ga Fabrairu, 1900, tare da Janar na Faransa da ke kewaye da Cronje a Magersfontein kuma yana hawa zuwa Kimberley. Harin De Wet a kan rundunar karusar shanu a Watervals Drift, wanda ya kama shanu 1600, bai dakatar da ruwa ba. An sauƙaƙe Siege na Kimberley a ranar 15 ga Fabrairu, kuma Cronje ya mika wuya tare da maza 4000 a Paardeberg
a ranar 27 ga watan Fabrairu. Ba da daɗewa ba bayan haka, an nada de Wet a matsayin Babban Kwamandan sojojin Free State. Ba za su iya ci gaba da ci gaba da Birtaniya zuwa babban birnin jihar Free State, Bloemfontein, wanda aka dauka ba tare da wata matsala ba a ranar 13 ga Maris, 1900.