The flag of the Natalia Republic was the official flag of this short-lived South African state, which existed from 1839 to 1843.

Emigrant Boers ('Voortrekkers') from the Cape Colony established an independent state in 1839, on territory conquered from the Zulus. They named it 'Natalia'. It is uncertain what flag – if any – they flew at first, but on 24 December 1839 they raised a new flag at Port Natal (now Durban. The same flag was raised in the capital, Pietermaritzburg, in January 1840.

British forces invaded the republic in May 1842 and occupied Pietermaritzburg two months later. The flag was probably discontinued at that time or shortly afterwards. After three years of military occupation, the United Kingdom formally annexed Natalia, as 'Natal', in May 1844.

Andries Pretorius, former Prime Minister of the Natalia Republic, and his followers, arrived in Potchefstroom after the annexation of Natal to the United Kingdom and brought with him the flag which saw continued use in Potchefstroom until it was relinquished in 1858. Wikipedia