<Ul> <Li> Strangford Loch (877) </Li> <Li> Cenn Fuait (915) </Li> <Li> Mag Femen (917) </Li> <Li> Áth Cliath (919) </Li> <Li> Sulcoit (968) </Li> <Li> Luimnech (968) </Li> <Li> Cathair Cuan (977) </Li> <Li> Tara (980) </Li> <Li> Glenmama (999) </Li> <Li> Clontarf (1014) </Li> </Ul> <Li> Strangford Loch (877) </Li> <Li> Cenn Fuait (915) </Li> <Li> Mag Femen (917) </Li>

When did the vikings migrate into western europe