“…Repeated soundings into the foundations of the fortifications at Isthmia, both along the Hexamilion and the Fortress wall, consistently yielded material that allows us confidently to date construction in the early years of the fifth century, An Tard, 8,2000 with a likelihood that this was carried out somewhere in the decade between 410 and 420. This evidence includes lamps, pottery, and coins, and it supports the general conclusion, based on examination of the architecture, that the entire fortification project was carried out at the same time.…”