The precession of the equinoxes is caused by the differential gravitational forces of the Sun and the Moon on the Earth. (sciencedaily.com)
During this time, rainfall was affected by the African monsoon which strengthened and weakened on a 23,000 year cycle driven by the precession of the equinoxes. (sciencedaily.com)
The precession of the equinoxes refers to the precession of Earth's axis of rotation with respect to inertial space. (sciencedaily.com)