The first modern concentration camps were created by the Spanish in 1896 as "reconcentrados" to house Cubans suspected of supporting insurgents during the Cuban War of Independence and the British during the Second Boer War to house Boers to prevent them from supporting the forces of the South African Republic and the Orange Free State. However, early examples of what could be termed "concentration camps" were utilized by the United States during their forced removal of Native Americans to temporarily house Indian tribesmen while it was decided where they would be forced to migrate to. According to historian Dan Stone, concentration camps were "the logical extension of phenomena that had long characterized colonial rule". Although the word "concentration camp" has acquired the connotation of the murder of those detained due to the Nazi concentration camps, the Spanish, British and American camps did not involve systematic murder of those in them. The German Empire also established concentration camps (), such as the one of Shark Island during the Herero and Namaqua genocide (1904–1907). The death rate of those sent to these camps was 45%, twice that of the British camps. Over time, concentration camps became more severe. The nineteenth-century professionalization of European armies led to "a doctrine of military necessity as justifying extreme violence", including against civilians considered a threat.