Complex sentence: During the Second Boer War, from 13 March to 11 May 1900, the town became the capital of the Orange Free State, and subsequently the site of a British concentration camp to accommodate Boer women and children.
Split into simpler sentences: During the Second Boer War, from 13 March to 11 May 1900, the town became the capital of the Orange Free State. Subsequently it became the site of a British concentration camp to accommodate Boer women and children.