Complex sentence: After the 66-65 BC wintering Pompey launched the Iberian campaign and according to Dio Cassius he crossed the river Cambysis, which Azerbaijani scholar Seyran Veliyev upon the accounts of Plinius the Elder and Ptolemy identifies with the Pirsaat River.
Split into simpler sentences: After the 66-65 BC wintering Pompey launched the Iberian campaign. According to Dio Cassius Pompey crossed the river Cambysis, which Azerbaijani scholar Seyran Veliyev upon the accounts of Plinius the Elder and Ptolemy identifies with the Pirsaat River.