An interesting discussion. 
 Christiansen is a Fellow of Oxford University and considered an expert in this subject. His research is magnificent. Not sure who William Urban actually is, although his account of the Livonian wars in The Baltic Crusade is a good read. But Krollmann's The Teutonic Order in Prussia (Elbing, 1938) states categorically that Memel is a Teutonic Knights foundation (as does von Treitschke). The preamble to the Versaille discussions states that "Memel was founded in 1252 by the Teutonic Knights" (refer: The Peace Settlement in the Polish-German Borderlands, Professor Ian F.D.Morrow, 1936). Given the degrees of cop-operation between the two, related, Orders it is probable that the northern Order may have garrisoned Memel from time to time in order to release Teutonic Knights for crusades against the Lithuanians and Pskovians. But it was a Teutonic Knights castle. 

 Whilst this may indeed be the English-language Wikipedia there are a great many foreign names which have never been changed into an English equivalent. "Curonian" is definitely NOT English, but an invention. The Encyclopaedia Britannica (A & C Black, London) produced a huge set of finely detailed maps in 1903, and whilst they refer to a great many foreign names (such as East Prussia instead of Ost Preussen), Konigsberg, for instance, was never changed from its German name. This also applies to the Kurische Nehrung peninsular which, since the middle of the 13th century has been called that in all atlases in Britain, including even our Robinson's Atlas of 1939. The simple fact is that you cannot hope to erase almost 700 years of German culture from this region in this silly way. Its time to grow up. I'm 100% behind our anonymous friend, above.