Complex sentence: In the Imperial era, the Sun-god was patron of the Circus and its games, and his sacred obelisk towered over the arena; it was set in the central barrier, close to his temple and the finishing line.
Split into simpler sentences: In the Imperial era, the Sun-god was patron of the Circus and its games. His sacred obelisk towered over the arena; it was set in the central barrier, close to his temple and the finishing line.