The technique known today as primary directions is one of the most ancient and renowned methods of astrological forecasting, and also one of the most powerful. From classical antiquity throughout the Middle Ages and Renaissance, and even into the twentieth century, all the great names of western astrology have worked with primary directions. It was the predictive technique of Dorotheus and Ptolemy, of Masha'allah and Abu Ma'shar, of Regiomontanus and Placidus, of Morin de Villefranche and William Lilly. To understand the Old Masters of astrology, we must understand primary directions. Students of traditional astrology have often been deterred by overly mathematical presentations from approaching the important subject of directions. This comprehensive study explains the principles of primary directions in an accessible form, illustrating them by practical examples. It also draws on many original source texts to outline the historical origins and development of the technique, and shows how it has been reinterpreted and occasionally misunderstood. A full glossary and appendices with software reviews as well as formulae for manual calculations complement the text. The craft of the Old Masters can still be learnt.