 Complete the following phrase:  Sun and Moon cults were probably represented at the Circus from its earliest phases. Their importance grew with the introduction of Roman cult to Apollo, and the development of Stoic and solar monism as a theological basis for the Roman Imperial cult. In the Imperial era, the Sun-god was divine patron of the Circus and its games. His sacred obelisk towered over the arena, set in the central barrier, close to his temple and the finishing line. The Sun-god was the ultimate, victorious charioteer, driving his four-horse chariot quadriga through the heavenly circuit from sunrise to sunset. His partner Luna drove her two-horse chariot biga; together, they represented the predictable, orderly movement of the cosmos and the circuit of time, which found analogy in the Circus track. In Imperial cosmology, the emperor was Sol-Apollos earthly equivalent, and Luna may have been linked to the empress. Lunas temple, built long before Apollos, burned down in the 