Complex sentence: After the Battle of Baecula and Hasdrubal Barca's departure, further Carthaginian reinforcements were landed in Spain in early 207 BC under Hanno, who soon joined Mago Barca, together they were raising a powerful army by heavy recruiting of Celtiberians.
Split into simpler sentences: After the Battle of Baecula and Hasdrubal Barca's departure, further Carthaginian reinforcements were landed in Spain in early 207 BC under Hanno, who soon joined Mago Barca. Together they were raising a powerful army by heavy recruiting of Celtiberians.