It was the product of the reunion of Daniel François Malan's Gesuiwerde Nasionale Party (English: Purified National Party) and J.B.M.
Hertzog's breakaway Afrikaner nationalist faction of the United Party in 1940.
Hertzog split away in 1939, however, because he was a Nazi sympathizer and he could not tolerate the idea of entering World War II on the side of the British.
[1] Hertzog briefly led the new party but resigned after Malan and his faction rejected Hertzog's proposed platform of equality between British South Africans and Afrikaners.
The Herenigde Nasionale Party gained popularity after the war and unexpectedly won the elections of 1948 with a majority of seats but a significant minority of the popular vote.