Definition of Mediastinum. Mediastinum: The area between the lungs. The organs in the mediastinum include the heart and its large veins and arteries, the trachea, the esophagus, the bronchi, and lymph nodes. Search MedTerms:
The Pax Romana ended because the Roman state had ceased to grow. Boundaries had been set for the Empire, and for the first time the army had become a drain on the econom â¦ y of Rome. Till this point the army provided new slaves and riches from conqured countries.
The Pax Romana (Roman Peace) was a time of peace and prosperity hitherto unknown and it would last For over 200 years. Augustus ruled the empire from 31 BCE until 14 CE when he died. In that time, as he said himself, he found Rome a city of clay but left it a city of marble..