Waterford - Port Láirge - Lárag's port
Viking raiders first established a settlement near Waterford in 853. It and all the other longphorts were vacated in 902, the Vikings having been driven out by the native Irish.
However, the Vikings re-established themselves in Ireland at Waterford in 914, led at first by Ottir Iarla (Jarl Ottar) until 917, and after that by Ragnall ua Ímair and the Uí Ímair dynasty, and built what would be Ireland's first city. Among the most prominent rulers of Waterford was Ivar of Waterford.
As far as the place-name goes, the Irish is simple although we're not sure who Lárag was but there is confusion about the name the Vikings gave it with a choice between Ve
r with the first element meaning a ram or a wether (a castrated ram) or whether it means a weather-protected fjord.