When war was actually declared, General Meyer, with his commandos, was on the Transvaal border near his farm, and he opened hostilities by making a bold dash into Natal and attacking the British army encamped at Dundee.  The battle was carefully planned by Meyer, and it would undoubtedly have ended with the capture of the entire British force if General Erasmus, who was to co-operate with him, had fulfilled the part assigned to him.  Although many British soldiers were killed and captured, and great stores of ammunition and equipment taken, the forces under General Yule were allowed to escape to the south.  General Meyer followed the fleeing enemy as rapidly as the muddy roads could be traversed, and engaged them at Modderspruit.  There he gained a decisive victory, and compelled the survivors to enter Ladysmith, where they were immediately besieged.  Meyer was extremely ill before the battle began, but he insisted upon directing his men, and continued to do so until the field was won, when he fell from his horse, and was seriously ill for a month.  He returned to the front, against the advice of his physicians, on December 24th, and took part in the fighting at Pont Drift, Boschrand, and in the thirteen days’ battle around Pieter’s Hill.  In the battle of Pont Drift a bullet struck the General’s field-glasses, flattened itself, and dropped into one of his coat pockets, to make a souvenir brooch for Mrs. Meyer, who frequently visited him when no important movements were in progress.

When General Joubert and his Krijgsraad determined to retreat from the Tugela and allow Ladysmith to be relieved, General Meyer was one of those who protested against such a course, and when the decision was made Meyer returned to the Tugela, and remained there with his friend Louis Botha during the long and heroic fight against General Buller’s column.  Meyer and Botha were among the last persons to leave the positions which they had defended so long, and on their journey northward the two generals decided to return and renew the fight as soon as they could reach Modderspruit and secure food for their men and horses.  When they arrived at Modderspruit they found that Joubert and his entire army had fled northward, and had carried with them every ounce of food.  It was a bitter disappointment to the two generals, but there was nothing to be done except to travel in the direction of the scent of food, and the journey led the dejected, disappointed, starved generals and burghers north over the Biggarsberg mountains, where provisions could be secured.

During the long period in March and April when neither Boers nor British seemed to be doing anything, General Meyer arranged a magnificent series of entrenchments in the Biggarsberg mountains which made an advance of the enemy practically impossible.  Foreign military experts pronounced the defence impregnable and expressed the greatest astonishment when they learned that Meyer formulated the plans of the entrenchments