Ancients
Valentinian I (AD 364-375). AV solidus (4.41 gm). Trier, ca. AD 374-375. Rosette-diademed, draped, and cuirassed bust of Valentinian right / Valentinian I and Valens enthroned facing, holding a globe between them; above throne, Victory facing with wings spread, palm below; TROBS. RIC 17e. Depeyrot 43/1. NGC Choice VF 5/5 - 4/5.This is one of the first examples of the "Two Emperors Enthroned" reverse type that would be repeated through the next several reigns. Rival factions in the Roman Army demanded that Valentinian appoint another emperor, his brother Valens. At this point, the collegiate emperorship, like Diocletian's Tetrarchy, was theoretically not based strictly on territory, but it quickly settled into a de-facto split along east - west lines.
Estimate: 600-800 USD