How did the roman empire changed since the reign of trajan

The Roman Empire changed because of the Trojans out smarting them with the "Trojan Horse". The Trojan Horse was a HUGE statue of a horse that was placed in front of the Roman Empire gates, and had a letter stating that it was a gift. The guards brought the horse in, and the next thing you know, all of the Trojans came OUT of the horse, attacked, and won.