Complex sentence: The original books in Rome were destroyed by fire in 83 BC, were recreated in 76 BC by envoys sent by the Roman Senate throughout the antique world, and existed until AD 405, but little is known of their contents.
Split into simpler sentences: The original books in Rome were destroyed by fire in 83 BC, which resulted in an attempt in 76 BC to recollect them when the Roman senate sent envoys throughout the world to discover copies. This official copy existed until at least AD 405, but little is known of their contents.