IAU Division I includes Commission 4 (Ephemerides), Commission 7 (Celestial Mechanics and Dynamical Astronomy), Commission 8 (Astrometry), Commission 19 (Rotation of the Earth) and Commission 31 (Time). The Division has in addition five Working Groups on, respectively, Future Development of Ground-Based Astrometry, Nomenclature for Fundamental Astrometry, Definition of Coordinated Universal Time, and Precession and the Ecliptic.