H.C.W. Vermaas went with General Cronje to the south-western border at the outbreak of the war and was present at the first battle at Kraaipan. After a short stay at Mafeking he was transfered to Kimberley and later to the Free State. He was at most of the battles there, as well as Scholtznek and Magersfontein. Here at Magersfontein his brave Veldkornet Johannes Coetzee and a few other burgers died.
Later he was present at the battles of Kimberley, Kalmberg, Roodepoort, Donkerhoek, Silkaatsnek, Grootplaats Marico, Wonderfontein, Witspruit, Hartsrivier, Brekspruit and Roodewal where the brave Commandant Potgieter died.
He was wounded twice, once with a bullet filled with dinamite in the hand.
Four of his horses were shot dead under him.
He was till the end of the war busy with operations at the western districts