The thistle is the flower of Scotland and according to legend was adopted as the emblem after a battle with the Norwegians.  For hundreds of years much of Scotland was part of Norway until King Alexander III proposed to buy back the Western Isles and Kintyre from the Norse King Haakon IV.  This angered Haakon so in 1263 he set off with a fleet of longships but was forced to land at night in stormy weather at Largs. Intending to surprise the sleeping Scots the invaders took off their shoes so they could creep quietly but unfortunately one of the Norsemen stood on a prickly thistle and shrieked in pain.  This alerted the sleeping Scots who went on to defeat the Vikings and as a result the thistle became the national symbol.