He appears to have become king of the Catuvellauni ca. 20 BC, ruling from Verulamium (St. Albans). For a brief period ca. 15-10 BC he issued coins from Camulodunum (Colchester)
SOURCES: Wikipedia.org (Tasciovanus) Geoffrey of Monmouths' 'Historia Regum Britanniae' (as Tenvantius, son of Lud).