Complex sentence: With Roman aid, Knossus became once more the first city of Crete, but, in 67 BC, the Roman Senate chose Gortys as the capital of the newly created province Creta et Cyrene.
Split into simpler sentences: With Roman aid Knossus became once more the first city of Crete. But in 67 BC the Roman Senate chose Gortys as the capital of the newly created province Creta et Cyrene.