"Hellenistic Astrology was developed around the five visible planets: Mercury, Venus, Mars, Jupiter and Saturn, as well as the luminaries, The Sun and The Moon. These seven bodies were often treated as a group, and generally referred to together as the 'seven planets' or 'wandering stars'. This terminology arose from the fact that if you look up at the night sky over a long period of time you will notice that while most of the stars stay fixed relative to one another, there are some that move slowly, and seem to wander about, passing by other stars in the process. Thus, the planets became known as the wandering stars, while the rest become known as the fixed stars." From Hellenistic Astrology: The Study of Fate and Fortune by Chris Brennan The Archetypal principles which correspond to the seven Gods known to the ancients (defined in the articles below) "were well established in their basic character from the beginning of the Western astrological tradition in the early Hellenistic era, from around the second century BCE onward, and their meanings continued to develop and be elaborated through later antiquity, the medieval era, and the Renaissance not only in astrological practice and esoteric writings but in the art, literature, and evolving and scientific thought of a larger culture. Of the seven, Saturn was the most distant, slowest-moving planet visible to the naked eye, and its complex of meanings directly reflected that status: the ruler of boundaries and limits, of finitude and endings, of distance, slowness, age, time, death and fate. Many ancients, such as the Gnostics and initiates of the mystery religions, believed that beyond Saturn existed another realm ruled by a greater, more encompassing deity, a domain of freedom and immortality beyond the constraints of fate and death." From Cosmos and Psyche: Intimations of a new world view by Richard Tarnas The meanings and significations of the more recently discovered planets inhabiting that realm beyond, Uranus, Neptune and Pluto, have initially been a mystery, and so our current understanding of the archetypal significations has had to take a different path. Meaning has been formulated through systematic observation and empirical research. Through witnessing the events and experiences which have regularly occurred, and recording the patterns of those experiences in relation to where The Gods are and what The Gods are doing. The significations reveal themselves and a consensus in the labelling of those significations is found. My teacher, Adam Elenbaas (of Nightlight Astrology), posits that the traditional seven Gods provide the astrologer with ample evidence to inform an answer to whatever question is asked of the chart, whether in relation to the birth chart or the timings of events, however Uranus, Neptune and Pluto can be included to enhance and corroborate the requested answers. In my practice I have come to the same conclusion. As such, in a birth chart reading I prefer to keep things simple and focus on the traditional seven Gods. I add in Uranus, Neptune and Pluto to a forecast reading because usually the big events and transformations in our lives occur, thanks to their obvious correspondence to either Uranus, Neptune or Pluto, which makes it easier and clearer to visually time those events in such a way that is useful and reliable.