original: When South Africa became a republic in 1961, Pretoria remained its administrative capital.
simplifications: When South Africa became a republic in 1961, Pretoria stayed its administrative capital. After South Africa became a republic, Pretoria remained as a capital city. Pretoria stayed capital when South Africa became a republic. South Africa became a republic in 1961. Pretoria remained its administrative capital. When South Africa became a republic in 1961, Pretoria stayed its capital. Pretoria stayed the administrative capital of South Africa when it became a republic in 1961. Pretoria remained South Africa's capital after it became a republic in 1961. Pretoria remained the South African capital once it became a republic in 1961. South Africa became a republic in 1961. Pretoria remained its administrative capital. Pretoria remained the official capital of South Africa after it became a republic in 1961.