Belief in demons was widespread in the ancient world. They were thought of as natural rather than supernatural beings.
Socrates described his philosophical inspiration as the work of a personal benign demon.
Augustine believed that witches were the offspring of …demons having unlawful sexual congress with women.
In the Middle Ages, nearly everyone believed in such stories. The demons were called devils or fallen angels. The demonic seducers of women were labeled incubi; of men succubi. There are cases in which nuns reported a striking resemblance between the incubus and the priest-confessor, or the bishop, and awoke the next morning… having been polluted as if… with a man.
The external reality of demons was almost entirely unquestioned from antiquity through late midieval times.
…infamous Bull of 1484, Pope Innocent VIII …