He successfully invaded the Cape Colony, failed to prevent the British relief of Mafeking, and fought to the end up to the Battle of Rooiwal.

During the First World War Liebenberg criticised the policy of the Botha government to attack German South West Africa but did not condone the Maritz rebellion.

[8] Steenkamp had considered the recruitment of up to 6000 soldiers in the Cape Colony as the priority, before going south and cutting the railway and British lifeline between De Aar and Hopetown.

[11] Liebenberg recruited 200 men in Griekwastad on 28 February 1900 and chased away 500–700 British troops under Colonel Adye at the farm Houwater, some 40 kilometers north-west of Britstown.

After the British occupation of Bloemfontein on 13 March 1900, the capital of Orange Free State, Liebenberg returned to Griqualand West and established his headquarters at Rooidam.

[19] However, two horses on the north bank of the Molopo bolted under British cannon fire, leading the Rustenburg and Marico burgers there to retreat in a hurry.

[21] Liebenberg participated with his Griqualand troops in the lost Battle of Diamond Hill (Slag van Donkerhoek), where Louis Botha ordered a retreat to Bronkhorstspruit on 12 June 1900.

[2][24] Generals Christiaan De Wet and Liebenberg combined their forces to a total of 1500 men and laid a siege around Frederikstad on 20 October 1900 but had to flee after five days when British reinforcements under Lt.-Col. H. T. Hicks arrived.

[3] During the First World War Liebenberg criticised the policy of the Botha government in a number of public speeches but did not condone the Maritz rebellion.