Apartheid, a form of institutionalised white supremacy, was bought into South African law in 1948. Apartheid allowed for the white minority to be completely dominant while oppressing Black people, Asian people, and people of colour. Non-whites couldn't vote. They were forcibly removed from their homelands. They were not allowed to use white facilities, as everything from water fountains to hospitals was completely segregated.
Black South Africans faced countless atrocities at the hands of their white supremacist government, and anyone who spoke up against it was either thrown in prison, or killed. Even children weren't safe, as protesting Black South African school children were shot and killed for standing up against oppression.
As the decades went on, the international community became more and more vocal about the atrocities being committed in South Africa. Sanctions were placed on the nation, and many countries ceased all sporting relations with them. One notable exception was New Zealand.
Both New Zealand and South Africa were powerhouses on the rugby field and they weren't going to let the apartheid regime get in the way of a good bloody game of rugby. New Zealand initially sent all-white rugby teams to play in South Africa, before allowing some of their Polynesian players to join under the classification of "honorary whites".
In the same month that black school children were murdered by South African police while protesting apartheid, the New Zealand rugby team turned a blind eye and continued on a rugby tour of South Africa, insisting that sports had to be kept separate from politics.
Back home in New Zealand, oppressed people of color, and allies standing in solidarity fought to stop New Zealand's sporting relations with the white supremacist nation of South Africa. They found harsh opposition in New Zealanders that either supported white supremacy, or were willing to ignore it for the sake of a rugby match.
In 1981, the Springboks (South Africa's national rugby team), set out for a tour of New Zealand despite discouragement from the Commonwealth and the United Nations.
New Zealand was split down the middle as anti-apartheid protestors fought to stop the tour, police used extreme force against these peaceful protestors, and pro-tour rugby fans threatened death against them.
This is Injustice.
Resources
Patu! Film - Merata Mita
The 1981 Springbok Tour - New Zealand History
The 1981 Springbok Tour Schedule - New Zealand History
Clash on Molesworth Street - New Zealand History
Three things you didn't know about the Springboks Tour - Leonie Hayden, The Spinoff
Errol Tobias paved the way for Black Springbok Players 40 years ago - Nick Said, Daily Maverick
40 years on: Photographer Ans Westra in the thick of the 1981 Springbok protest - Zoë George, Stuff NZ