The thirty or forty years after 680 saw the production and circulation of the "primary series" of sceattas, which were generally of good metal quality and weight They were largely minted in Kent and the Thames Estuary, though a few were produced in Northumbria bearing the name of King Aldfrith The "secondary series", struck from to saw a massive expansion of minting all over southern and eastern England to every major Anglo-Saxon kingdom. One or more types can be attributed with more or less confidence to Wessex, Mercia, Sussex, Essex, Kent, Northumbria, and East Anglia.