He was born on 19 January 1896 at Houtenbeck in the Merweville district of the Cape Colony to Marthinus Frederik Erasmus and his wife Hester Maria Jacoba Maritz.

[2] He negotiated the Simonstown Agreement, the return of the naval base from Royal Navy control.

[5] He was widely considered to be incompetent[6] and was very unpopular[6] because of his broad changes to the military to remove what he called the "British Influence".

[6] This included the removal of items such as the Red Tabs (Rooi Luise)[7] and the retrenchment or firing of numerous English-speaking officers and the appointment of Afrikaner ones in their place.

[2] After his term as Minister of Justice, which ended upon acceptance of his own request for retirement, he was appointed Ambassador to Italy from 1961 until 1965.