Complex sentence: He left his troops in the care of his friend, Menandro, and upon returning, he was ambushed by 30,000 soldiers under Adolfo's orders and was imprisoned for 18 days.
Split into simpler sentences: He left his troops in the care of his friend, Menandro. Upon returning, he was ambushed by 30,000 soldiers under Adolfo's orders and was imprisoned for 18 days.