Subspecies is the only taxonomical category inferior to species which application is governed by the International Code of Zoological Nomenclature. Although the first attempts to use it are dated by the end of XVIII century, it becomes regularly applied only by the middle of XIX century, along with trinomial nomenclature. At that, the current sense of the term, i.e. subspecies as a morphologically and spatially separated population group or as a synonym for "geographical race", has become established even later, by the end of XIX century. The concept of polytypic species, which has already taken shape in 1900s (in the works by ornithologist E. Hartert and entomologist K. Jordan), has been incorporated later into the modern evolutionary synthesis. The peak of the concept popularity fell on 1940-50s, then the evident crisis of subspecies systematics began to show, and is still showing nowadays, especially in systematics of invertebrates. The reasons behind the drop of subspecies category popularity are discussed, among them the emergence of novel species concepts where the rank of subspecies is not used (the phylogenetic species concept), impossibility to verify the validity of previously described subspecies by means of statistics or molecular systematics, etc. Nevertheless, in systematics of vertebrates, the category of subspecies still remains called-for.