The notebook written by Nehemiah Wallington, an English Puritan, recounts the fate of women accused of having relationships with the devil at a time when England was embroiled in a bitter civil war.
The document reveals the details of a witchcraft trial held in Chelmsford in July 1645, when more than a hundred suspected witches were serving time in Essex and Suffolk according to his account.
"Divers (many) of them voluntarily and without any forcing or compulsion freely declare that they have made a covenant with the Devill," he wrote.
"Som Christians have been killed by their meanes," he added.
Of the 30 women on trial in Chelmsford, 14 were hanged.
Wallington also recounts the experiences of Rebecca West, a suspected witch who confessed to sleeping with the devil when she was tortured because "she found her selfe in such extremity of torture and amazement that she would not enure (endure) it againe for the world." Her confession spared her.