A graduate of Victoria College (now Stellenbosch University), Beyers migrated to the Transvaal, where he was naturalized and practiced as a lawyer. Joining the Boer forces in 1899, he rose rapidly to the rank of general and commanded the forces in the northern Transvaal. A staunch Afrikaner, Beyers joined Louis Botha's party, Het Volk (“The People”), after the war and was elected speaker of the Transvaal Parliament (1907).

The Union of South Africa was formed in 1910, and when the Union Defence Force was established two years later, Beyers was made the commandant general. Beyers always objected to Botha's conciliatory policy toward Britain. With the outbreak of World War I, when Botha's government decided to aid the British by conquering German South West Africa, Beyers resigned (Sept. 15, 1914). Botha and his defense minister, Jan Smuts, failed to mollify Beyers and other Afrikaner nationalists, who then resorted to armed protest. While trying to elude government forces during the short-lived rebellion, Beyers drowned in an effort to cross the Vaal River.