Theodore Barrows is a minor character in Clock Tower. He is not mentioned in the game, but rather, the novelization of the game.
Theodore was very interested in religion and wrote four books. One of them in part touches upon what one could call the primitive religious consciousness of the Europeans (even if there was not a sense of modern Europe at the time.)
Theodore was part of a demonic cult who praised a god called "Great Father" and was very afraid of death, likely due to the trauma from being in the war. Rumor has it that the dark god demanded sacrifices. As a result, he would abduct children within the country of England and use them in demonic rituals, some of which include cannibalism, torture and massacre; as he believed that he would gain immortality by doing so. Rumors of Theodore's inhuman ways eventually spread among the populace.
It is unclear how Theodore died. Many rumors circulated about Theodore's death. That he had sacrificed the children to a dark god, but that he finally was forced to sacrifice himself to the god of his heathen religion. Or that his relatives, afraid that the king might hear of Theodore's deeds, poisoned him. Or that they drowned him in his bathtub. And so on.
It should have all ended then, but the dark god Theodore had summoned continued to haunt the Barrows clan. This also left a curse within the Barrows family: for each generation of the Barrows, a demonic child would be born into the family and continue the massacre Theodore had started many years ago.