British refused, Kruger declared war against Britain, Britain received assistance from its possessions Australia, and Canada, as well as Natal and the Cape Colony. The Second Boer War was a watershed for the British Army in particular and for the British Empire as a whole. The British used concentration camps where women and children were held without adequate food or medical care. The abhorrent conditions in these camps caused the death of 4,177 women and 22,074 children under 16; death rates were between 344 and 700 per 1000 per year. The Treaty of Vereeniging was signed on 31 May 1902. The treaty ended the existence of the ZAR and the Orange Free State as independent Boer republics and placed them within the British Empire. On 20 May 1903, an Inter Colonial Council was established to manage the colonies of the British Government. The Boers were promised eventual limited self-government and this was granted in 1906 and 1907. The Union of South Africa was established in 1910. Maritz Rebellion, 1914–1915 The Maritz rebellion was an armed insurrection which occurred in South Africa in 1914 at the start of World War I. It was led by Boers who created a provisional government and sought to reestablish the South African Republic in the Transvaal. Many members of the South African government were themselves former Boers who had fought with the Maritz rebels against the British in the Second Boer War. The self-proclaimed rebel republic allied with Germany, with whom Britain and South Africa were at war. Boer Commandos operated in and out of bordering German South West Africa. By 1915, the rebellion had failed, and the ringleaders received heavy fines and terms of imprisonment. Economy and transport The discovery of gold during the Witwatersrand Gold Rush in 1886 changed the economic fortunes of the formerly impoverished ZAR. The city of Johannesburg was founded as a gold mining town in the same year. Within 10 years it grew into the largest city in Southern Africa, surpassing Cape Town. The discovery of gold allowed the construction of a railway network in the ZAR. The east–west railways in the ZAR, and notably the line from Pretoria to Lourenço Marques in Portuguese East Africa, were constructed by the Netherlands-South African Railway Company. The construction of the Pretoria-Lourenço Marques line allowed the ZAR access to harbour facilities not controlled by the British Empire, a key policy of Paul