Also called Liber AL vel Legis, or Simply Liber Legis. In this book the Magical Philosophy of Thelema was first divulged to the world. A communication was received by Rose Edith Kelley and written down by her husband Aleister Crowley in Cairo, Egypt, in 1904 on three consecutive days, April 8th, 9th and 10th of that year. This communication consisted of three small chapters that were received at noon, one on each of the three days. Within this writing, with its strange phrases and multi-layered meanings, a new Law for a new Aeon was proclaimed. Although the book is commonly referred to as "the Book of the Law", Babalon always refers to it as "the Book of Law", which follows the title as given within the text of the book itself. You can read the Book of Law here.