Leabhar Maidin Glas
(Green Morning Book)
This somewhat unlucky tome — well, unlucky for its readers — was the target of numerous thefts, the occasional assassination, at least one war; and even today it’s still valuable as a historical heirloom. The book is in Middle Irish, and dates back to the 10th Century AD; and for its time the Leabhar Maidin Glas was a potent tome full of fell rituals and practices. However, the practices in question were all in the field of agriculture, if you’ll pardon the pun; there’s absolutely nothing magical and esoteric in the book at all. Well, nothing magical or esoteric, here in the modern era. Back in the day before scientific agronomy the tips found in the book would be remarkably good at increasing crop yields and breeding livestock, which is why so many petty noblemen kept raiding each other in order to get their hands on the only copy.