It depends on who you ask and what criteria you use to determine who is the greatest. Some people might say that the greatest historical figure is someone who changed the world for the better, such as Mahatma Gandhi or Nelson Mandela. Others might say that the greatest historical figure is someone who was incredibly influential and had a major impact on the course of history, such as Julius Caesar or Alexander the Great. Ultimately, it is up to each individual to decide who they believe is the greatest historical figure.