After seven years of investigation, Alan Leo abandoned the various methods advocated by the different schools of exoteric astrology and began adopting a system, based on his own study and experience, which was centered on what is known as the progressed horoscope. The progressed horoscope is based on the "Day For A Year" system of progressing the nativity, a system first employed by the ancient Arabian astrologers. If not the ideal system of prediction, claimed Leo, it is certainly the most simple and on the whole the most satisfactory astrology system ever put forward. This Cosimo Classic is a reprint of the First Edition, originally published in 1905. ALAN LEO (1860-1917) is often called "the father of modern astrology." He was born a Leo Sun with Virgo Rising, in Westminster, London and given the name William Frederick Allan. He taught himself astrology at the age of 28 and within a decade he was sole proprietor of the enormously successful Modern Astrology Publishing Company and its magazine, which eventually became known as Modern Astrology. His thirty books on the subject fostered a revival in legitimate astrology in the twentieth century.