During 164 AD, Lucius Verus was leading an army to conquer the city of Seleucia in what is now Iraq. Little did they know that there was a virus spreading and soldiers started to have a severe fever and visible sores that spread across their entire body. Most scholars now agree the disease was smallpox, but it is commonly referred to as the Antonine Plague. The offensive military campaigns were postponed, and Lucius Verus was infected leading to his death. The virus outbreak leads to the downfall of the Roman Empire.