▁ 1 9 0 5 ▁as ▁the ▁naval ▁equivalent ▁to ▁the ▁five - star ▁rank ▁of ▁the ▁Gener alf eld mar sch all ▁( General ▁field ▁mar sh all ) ▁OF - 1 0 ▁in ▁He er ▁( en : ▁Army ). ▁Hans ▁von ▁Ko ester ▁was ▁the ▁first ▁German ▁flag ▁officer ▁to ▁hold ▁this ▁rank . ▁Wilhelm ▁II . ▁would ▁wear ▁the ▁uniform ▁of ▁a ▁Groß ad mir al ▁on ▁occasions . ▁Since ▁as ▁Emperor ▁he ▁was ▁Commander - in - Ch ief ▁of ▁the ▁Navy ▁and ▁thus ▁not ▁subject ▁to ▁prom ot ions . ▁ ▁General ad mi rale ▁ ▁Ad mi rale ▁ ▁The ▁rank ▁of ▁adm iral ▁was ▁the ▁highest ▁rank ▁until ▁the ▁rank ▁of ▁Groß ad mir al ▁was ▁introduced ▁in ▁ 1 9 0 5 . ▁Prince ▁Ad al bert ▁of ▁Pr uss ia ▁was ▁the ▁first ▁and ▁only ▁adm iral ▁of ▁the ▁Pr uss ian ▁Navy ▁and ▁later ▁the ▁Navy ▁of ▁the ▁North ▁German ▁Confeder ation . ▁The ▁rank ▁was ▁not ▁used ▁in ▁the ▁Imperial ▁German ▁Navy ▁until ▁ 1 8 9 2 . ▁In ▁the ▁Reichs marine ▁Admir al ▁was ▁again ▁the ▁highest ▁of ▁three ▁flag ▁officer ▁ranks . ▁With ▁the ▁creation ▁of ▁the ▁Kriegs marine ▁and ▁the ▁expansion ▁of ▁the ▁fleet ▁a ▁new ▁rank , ▁General ad mir al , ▁was ▁introduced ▁in ▁ 1 9 3 6 , ▁followed ▁by ▁the ▁rank ▁of ▁Groß ad mir al ▁in ▁ 1 9 3 9 . ▁Thus ▁the ▁rank ▁of ▁adm iral ▁became ▁the ▁third