The history of the nomenclatural type concept and the principle of typification are outlined following examination of articles, recommendations and appendices in editions (and Japanese versions) of the International Code of Zoological Nomenclature (ICZN), the Règles Internationales de la Nomenclature zoologique, and the antecedent Stricklandian and Blanchard Codes. For family-group names, typification first appeared as a recommendation of the Stricklandian Code in 1843, subsequently becoming a criterion for availability following publication of the Blanchard Code in 1889. Typification of genus-group names also followed publication of the Stricklandian Code, being considered a criterion for availability since 1930. In species-group names, however, the explicit fixation of name-bearing types (holotypes and syntypes) has been included in the appendices of the Règles since 1913, being a recommendation in the first to third editions of the ICZN, and now (fourth edition), a criterion of availability of names published after 1999. Reasons are considered why the principle of typification was applied as a criterion for availability for species-group names far later than for family- and genus-group ones. The institution and development of public specimen registration systems in the UK and USA are also discussed.