▁of ▁sc rew ▁cor v ettes ▁to ▁expand ▁and ▁modern ize ▁its ▁fleet ▁of ▁cru ising ▁war ships . ▁In ▁total , ▁twenty - three ▁ships ▁of ▁the ▁type ▁were ▁built , ▁mostly ▁between ▁six ▁different ▁ship ▁classes . ▁The ▁first ▁two ▁ships , ▁the ▁, ▁were ▁built ▁in ▁the ▁early ▁ 1 8 6 0 s ▁as ▁Pr uss ia ▁began ▁to ▁prepare ▁for ▁an ▁event ual ▁conflict ▁with ▁Den mark ▁over ▁the ▁Schles wig - Hol stein ▁Question , ▁though ▁only ▁ ▁entered ▁service ▁in ▁time ▁for ▁the ▁Second ▁Schles wig ▁War ▁in ▁ 1 8 6 4 . ▁During ▁the ▁war , ▁Pr uss ia ▁purchased ▁the ▁two ▁s ▁that ▁had ▁been ▁secret ly ▁ordered ▁by ▁the ▁Confeder ate ▁States ▁Navy ▁from ▁France , ▁after ▁the ▁French ▁Emperor ▁Napoleon ▁III ▁blocked ▁their ▁delivery ▁to ▁the ▁Confeder ates . ▁The ▁three ▁ships ▁of ▁the ▁ ▁were ▁laid ▁down ▁in ▁the ▁late ▁ 1 8 6 0 s ▁and ▁early ▁ 1 8 7 0 s , ▁and ▁these ▁were ▁followed ▁by ▁two ▁s ▁in ▁the ▁early ▁ 1 8 7 0 s . ▁The ▁six - ship ▁ ▁was ▁built ▁in ▁the ▁mid - 1 8 7 0 s ▁to ▁early ▁ 1 8 8 0 s , ▁and ▁was ▁followed ▁by ▁another ▁group ▁of ▁six ▁ships , ▁the ▁. ▁A ▁further ▁two ▁vessels , ▁ ▁and ▁, ▁were ▁built ▁in ▁the ▁early ▁ 1 8 8 0 s ▁specifically ▁to ▁serve ▁as ▁training ▁ships , ▁a ▁role ▁that ▁many ▁of