Our concept of the structure and function of the normal and diseased brain has developed throughout the centuries. The first stage in the discovery of the brain stretched over three millennia, from the earliest descriptions by the Egyptians in the sixteenth century B.C. to the comprehensive anatomical treatise of Vesalius. The invention of the light microscope brought to the eye a previously invisible world, and heralded the beginnings of the systematic histological investigation of the immensely complex cellular networks of the brain. With the advent of electron microscopy, the organelles and connections of brain cells have been revealed, and the new era of molecular biology has begun. Neuropathology, which concerns itself with diseases of the brain, spinal cord, nerve and muscle, has enormously benefited from these developments to establish the morphological basis of diseases of the nervous system.