| ~350 BCE | Aristotle classifies animals into "with blood" and "without blood" | First systematic attempt to classify animals; basis for later vertebrate/invertebrate distinction |
| 1583 | Andrea Cesalpino publishes "De Plantis" | One of the first attempts at systematic plant classification based on fruit/seed structure |
| 1700 | John Ray introduces concept of "species" | Formalized the species concept based on morphological similarity and shared descent |
| 1707 | Birth of Carolus Linnaeus (Carl von Linné) | The "Father of Taxonomy" — would revolutionize biological naming |
| 1735 | Linnaeus publishes first edition of "Systema Naturae" | Introduced hierarchical classification; the beginning of modern taxonomy |
| 1753 | Linnaeus publishes "Species Plantarum" | Formal starting point for modern botanical nomenclature |
| 1758 | Linnaeus publishes 10th edition of "Systema Naturae" | Standard reference date for animal nomenclature; binomial system fully established |
| 1778 | Death of Carolus Linnaeus | Left a legacy of 10,000+ species named and classified |
| 1813 | A.P. de Candolle coins "taxonomy" in "Théorie élémentaire de la botanique" | Formal naming of the science of classification; distinguishes it as its own discipline |
| 1859 | Charles Darwin publishes "On the Origin of Species" | Evolutionary theory fundamentally changed taxonomy — classifications should reflect evolutionary history |
| 1866 | Ernst Haeckel proposes "Ecology" and uses "Phylum" | Introduction of the phylum rank into taxonomy |
| 1867 | International Code of Botanical Nomenclature first established | Beginning of codified rules for plant naming |
| 1895 | International Code of Zoological Nomenclature first established | Beginning of codified rules for animal naming |
| 1959 | Ernst Mayr formalizes "Biological Species Concept" | Species defined by reproductive isolation — still dominant in zoology |
| 1990s–present | Molecular phylogenetics revolutionises classification | DNA sequences used to reconstruct evolutionary trees; many traditional classifications revised |