Karen Hamaker-Zondag started her astrological practice in 1975. She is a founding member of two schools in Holland: an astrological school, Stichting Achernar, founded in 1980, and a school of Jungian psychology, Stichting Orderir, founded 1987.
A leading astrologer in Holland she also lectures extensively throughout the world and first began lecturing for the CPA in 1997. In 1999 she was invited to teach at the first real and official Astrological University in the USA, Kepler College, and be a member of the staff. This University is entitled to educate students for a Liberal Arts Degree, and will develop a program for a Masters Degree.
She is the author of many astrological books including Foundations of Personality, Psychological Astrology, Horary Astrology, The Yod Figure and Unaspected Planets and The Twelfth House.