Under Diocletian's expanded imperial "collegia", imperial honours distinguished both Augusti from their Caesares, and Diocletian (as senior Augustus) from his colleague Maximian. While the division of empire and "imperium" seemed to offer the possibility of a peaceful and well-prepared succession, its unity required the highest investiture of power and status in one man. An elaborate choreography of etiquette surrounded the approach to the imperial person and imperial progressions. The senior Augustus in particular was made a separate and unique being, accessible only through those closest to him.