Fear of the number 13.
Phobias appear to be present in all races and cultures although there may be some differences in the prevalence of particular types. They have been mentioned in early historical writings, particularly those of the Greeks and Romans. Allusions are made to phobias in later European writings but by the Middle Ages, they were often regarded as manifestations of demonic activity.
Although some phobias have always occurred, for example animal phobias and height phobias, others, particularly those relating to specific diseases or illnesses such as plague, syphilis and rabies, were once more common. These diseases were major killers in the past and, not surprisingly, people were afraid of them.