Complex sentence: He is said to have gestured to Italy, showing his soldiers where the Po was and the plains near it, and to have reminded them of Magilus, who had assured him of Gallic friendship and aid.
Split into simpler sentences: He is said to have gestured to Italy, showing his soldiers where the Po was and the plains near it. Reminding them of Magilus, who had assured him of Gallic friendship and aid.