Question: When did the country where the city where Steven Blankaart was born is located refuse to surrender Namibia?

<P0-S0> steven amsterdam (born in new york city on january 31, 1966) is an american writer. <P0-S1> he lives in melbourne, australia, where he also works as a palliative care nurse. <SEP> <P1-S0> Boschmanskop No 1+2 Dam, is an earth-fill type dam on the Woes-Alleen River, near Middelburg, Mpumalanga, South Africa. <P1-S1> It was established in 1995. <P1-S2> Its primary purpose is flood control and it is owned by Optimum Colliery Pullen's Hope. <SEP> <P2-S0> Steven Blankaart (24 October 1650, Middelburg – 23 February 1704, Amsterdam) was a Dutch physician, iatrochemist, and entomologist, who worked on the same field as Jan Swammerdam. <P2-S1> Blankaart proved the existence of a capillary system, as had been suggested by Leonardo da Vinci, by spouting up blood vessels, though he failed to realize the true significance of his findings. <P2-S2> He is known for his development of injection techniques for this study and for writing the first Dutch book on child medicine. <P2-S3> Blankaart translated works of John Mayow. <SEP> <P3-S0> eswatini, lesotho, botswana, namibia, and the republic of south africa form the southern african customs union (sacu), where import duties apply uniformly to member countries. <P3-S1> eswatini, lesotho, namibia, and south africa also are members of the common monetary area (cma) in which repatriation and unrestricted funds are permitted. <P3-S2> eswatini issues its own currency, the lilangeni (plural: emalangeni), which is at par with the south african rand. <SEP> <P4-S0> South Africa occupied the colony in 1915 after defeating the German force during World War I and administered it from 1919 onward as a League of Nations mandate territory. <P4-S1> Although the South African government desired to incorporate 'South-West Africa' into its territory, it never officially did so, although it was administered as the de facto 'fifth province', with the white minority having representation in the whites-only Parliament of South Africa, as well as electing their own local administration the SWA Legislative Assembly. <P4-S2> The South African government also appointed the SWA administrator, who had extensive powers. <P4-S3> Following the League's replacement by the United Nations in 1946, South Africa refused to surrender its earlier mandate to be replaced by a United Nations Trusteeship agreement, requiring closer international monitoring of the territory's administration (along with a definite independence schedule). <P4-S4> The Herero Chief's Council submitted a number of petitions to the UN calling for it to grant Namibia independence during the 1950s. <P4-S5> During the 1960s, when European powers granted independence to their colonies and trust territories in Africa, pressure mounted on South Africa to do so in Namibia. <P4-S6> In 1966 the International Court of Justice dismissed a complaint brought by Ethiopia and Liberia against South Africa's continued presence in the territory, but the U.N. General Assembly subsequently revoked South Africa's mandate, while in 1971 the International Court of Justice issued an "advisory opinion" declaring South Africa's continued administration to be illegal.