Introduction: The Historical Origins of Modern Immunology. Theories of Immunity: Origins of the Cell Selection Theories of Antibody Formation. One Cell-One Antibody. Roof of and Routes to Autoimmunology. The Cellular Basis of Immunity: The Mystery of the Lymphocyte. The Discovery of Thymus Function. The Discovery of MHC-Restricted T Cell Recognition. Two Signal Nodels of Lymphocyte Activation. Ontogeny of the Immune Response. The Molecular Basis of Immunity: The HLA Story. Early Investigations on Antibody Structure and Idiotypy. The Contribution of the Cytokine Concept to Immunology. Discovery of Antibody Gene Structure. Discovery of the T Cell Receptor. Immunology and Medicine: Organ Transplantation and the Revitalization of Immunology. Immediate Hypersensitivity, A Brief History. Tumour Immunology. Hepatitis B Virus and Vaccine. Studies of Thyroid Autoimmunity: Their Role in Shaping Modern Immunology.