Republic of Transvaal
Also known as the South African Republic, the Transvaal Republic was an independent state between 1852 to 1902. It won against the British during the Boer War I but eventually lost in Boer War II and became the Transvaal colony.
The British also suppressed an uprising called the Maritz Rebellion in 1915.
The state is now part of the Republic of South Africa and covers a number of provinces including Gauteng, Mpumalanga, Limpopo and North West.