eastern Mediterranean ancient societies.
A priest, priestess, or king was sacrificed and their blood and body given out to be eaten and drunk by other priests or selected people to ensure fertility of the soil and the people. Some of the blood was poured on the soil and pieces given to farmers to plant in their fields.
The fertility was intended not just for crops and herd animals, but to ensure continued life for the people who depended on those foods for survival. A cycle of life celebration, from conception to birth, life, death, and return to the soil to continue to feed the people. It was associated with societies that had dying and resurrecting gods, i.e. ancient Egypt (Isis), and very ancient Greece and Rome, before they became more advanced societies (Demeter, Aphrodite).
Outside of Egypt, Isis was known as Ishtar or Astarte.
A sublimated remnant of that ancient belief and custom exists in Christianity in the Eucharist, aka Holy Communion. "This is my body....This is my blood." Not a Jewish concept. It must have entered into Christianity from Greek and Roman converts in the early days of the church.
Human sacrifice in northern Europe was associated with appeasing the gods and with divination (discerning divine will, prophesying the future).
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