(All information from David Griffiths Vikings of the Irish Sea, The History Press 2010)
Historical records mentioned Viking groups in Waterford as far back as 860 and 892. The Annals of Ulster recorded apparently Viking fleets in the proximity of Ireland in 913-914, among which one of ‘sea-pagans’ that appeared in Waterford harbour, and, then, in 916, ‘a great and frequent increase in the number of heathens arriving’ at the enclave.
It has been believed that a small Viking fort or encampment occupied roughly what today forms the so called Viking Triangle, with Reginald’s Tower at its apex, as the basis on which the town grew later on, although no archaeological structural evidence of it has been found. Only in mid 11th century we have sudden ample evidence of a rapid Hiberno-Norse urbanization process.
The astonishing 9th century Scandinavian hamlet (possibly a comercial outpost) discovered in 2003-2005 during prospections for a bypass project at Woodstown, 8 km north of Waterford, on the bank of the river Suir, including objects, signs of structures and buildings, a ditched enclosure and the burial of a Viking warrior, was abandoned also in mid 11th century.