One of the ten
homelands or
Bantustans into which
apartheid-era
South Africa tried to
corral their Black population. This one was for the
Swazi people, and consisted of three small chunks of
Transvaal, two of which bordered the independent Kingdom of
Swaziland. In this case they did not try to grant it independence, but tried to
cede it to Swaziland.
KaNgwane was created on 8 October 1977 as AmaSwazi, under the leadership of chief councillor Enos Mabuza. Its homeland status was suspended from June to December 1982, as South Africa tried to negotiate its incorporation into Swaziland. But popular protest frustrated the plan (the South African regime was always happy to listen to what its less privileged citizens had to say, you'll remember), and AmaSwazi was restored.
It became self-governing on 31 August 1984 under the name of KaNgwane, which derives from Ngwane, the name of the main local branch of the Swazi people, and their eponymous founder. In 1991 Mabuza was replaced by Mangisi Zitha. Like the other homelands, it was fully absorbed back into democratic South Africa on 27 April 1994.
No flag was ever adopted for AmaSwazi or KaNgwane. The capital was KaNyamazane.
After the abolition of homelands, Swaziland did not drop its eagerness to receive KaNgwane, and it is now a border dispute between the countries, since Swaziland claims the region as traditional Swazi territory.
Furthermore, it seems that Swaziland is now officially known in the Swazi language as kaNgwane, though I cannot confirm this. Its official name was formerly Umbuso we Swatini; it is now referred to in some reliable places as Umbuso wakaNgwane, short form kaNgwane. But I can't find any reference to the actual change.