 Hiberno-Norse coins were first produced in Dublin in about 997 under the authority of King Sitric Silkbeard.The first coins were local copies of the issues of Aethelred II of England, and as the Anglo-Saxon coinage of the period changed its design every six years, the coinage of Sitric followed this pattern.Following the Battle of Clontarf in 1014 the Hiberno-Norse coinage ceased following this pattern and reverted to one of its earlier designs—the so-called 'long cross' type.