It was the tragedy of the Irish potato famine of 1845, in which 1m Irish perished when the potato crop on which they subsisted succumbed to blight.

起因是1845年爱尔兰马铃薯歉收，由于他们所赖以生存的马铃薯得了枯萎病，导致了一百万的爱尔兰人的死亡。