Today being St Patrick's Day (Lá le Pádraig in Irish) I decided to tell you a legend of St Patrick and fish (for the zoological element). In Scandinavia they eat a dish called lutefish. It is made of dried whitefish soaked in cold water (5-6 days), then in cold water and lye (2 days) and then cold water again (4-6 days). There are probably variations on these procedures.
According to the legend, St Patrick was mightily wroth with the Norse for attacking Ireland, so he gave them this fish dish in the hope the lye would kill them off.
It didn't, due to the doughty nature of the Norse. The legend is without foundation. St Patrick lived in the 5th Century, while the Vikings first came to Ireland in the 9th.