Events that took place in medicine during the 15th, 16th, and 17th centuries signaled the end of the Dark Ages. The Renaissance movement, spreading from Italy across Europe, ended the religious and public prohibitions that had prevented progress in medicine. Pioneer physicians and surgeons who gave their attention to discoveries in anatomy, physiology, and chemistry established the foundations for tumor pathology, surgical oncology, and medical oncology. This review is a summary of their accomplishments. Cancer 2011. © 2010 American Cancer Society.