Karl Ernst von Baer was a prominent 19th-century German biologist and naturalist, born on February 28, 1792. He is best known for his contributions to the field of embryology, particularly for formulating the Baer's Law, which states that the development of embryos of different species shows more similarities in the early stages than in later stages. His work laid the foundation for modern developmental biology. In addition to his research in embryology, von Baer made significant contributions to the study of zoology and geography. He was also involved in the establishment of the University of Königsberg and served as a professor there. His legacy continues to influence biological sciences today.