It was believed necromancy could obtain answers from the dead. Necromancy is performed mostly at midnight, especially if the night is filled with wind, rain, and lightning. This is not just for effect - spirits show themselves more readily in stormy weather. The majority of rituals involve lighting the scene with torches and creating a backdrop of deep contemplation and morbidity.
To raise a physical body from the other side, the process has to occur within one year of the death, otherwise, the necromancer would only be able to evoke the ghost, not the real person.
Despite it being a controversial form of black magic, many clerics in the Middle Ages studied necromancy as a legitimate form of education. Such medieval scholars believed necromancy could help them achieve many feats, including manipulating the minds of others. If they could communicate with the dead, scholars could study mind control, reanimation, emotions, and most importantly, the secrets of the universe and the afterlife.
Once the coffin was unsealed, the body would be removed and laid out with its head pointing east towards the rising sun, and its limbs assuming the position of crucifixion. A small dish of burning wine, mastic, and sweet oil would then be placed near the right hand of the body to promote conjuration. Incantations varied greatly between cultures, but all seemed to focus on commanding the spirit to move in the name of the deceased person and to answer the demands of the living.
Assuming the ritual goes according to plan, the body of the dead will slowly rise and dutifully answer the questions of the necromancer. The spirit should be rewarded for its cooperation by promising future peace, and the body would be burned afterward so it could never be reanimated again.
Should a necromancer want to raise a corpse from the cemetery, magic circles must be drawn around the grave and certain potent plants burned which included hemlock, aloe, Mandrake, and opium.
Nowadays there are people who claim they can speak to the dead. Modern necromancers cultivate working relationships with the dead through a medium and practice the ancient art of throwing bones, where the future is read based on their placement. Working with the energy of the dead is the contemporary version of reanimation, and it tries to avoid brutality and the desecration of burial sites.
The ancient art of bringing dead things to life is mostly gone. While there is plenty of literature on the subject and plenty of Occultists who claim to know the old ways, it's clear necromancy is quickly becoming a selective dark practice and not one for the faint of heart.
Em Hotep - Patrick Gaffiero