The thistle emerged as a Scottish emblem after a Danish invasion, long ago it was considered unwarlike to attack an enemy at night. The Danish invaders decided to attack barefooted and under the cloak of darkness to silently approach the unsuspecting Scots. While climbing up the hill, one solider stepped on a thistle (which is very sharp) and cried out waking the Scots, which allowed them to route out the Danes.

The Thistle inspired Scotland's own order of knighthood - The Most Ancient and Most Noble Order of the Thistle. Which is an order of chivalry as a means of awarding merit to those who deserve, either for achievement or service to the country. Achaiuys, King of the Scots in honor of St. Andrew (Patron Saint of Scotland), founded the order in 809.

The Order is now the highest Scottish Order in the British honours system. Its English equivalent is the Order of the Garter, and its Irish one was the Order of St Patrick. The latter became moribund when most of Ireland separated from the United Kingdom in 1922.

The Order is limited to sixteen Knights Companions, and more recently, Ladies Companions. Originally, the limit was twelve, but it was raised to sixteen in 1827. Some "supernumary" members, including members of the Royal Family, do not count toward the limit. Knights Companions use the post-nominal "KT," while Ladies use "LT."

For the order's great festivals (such as the order's annual services at St Giles High Kirk, Edinburgh, where its chapel is located), the knights and ladies wear elaborate insignia:

* The Collar is a gold chain consisting of representations of thistles alternating with representations of sprigs of rue. It is worn around the neck.
*The Badge Appendant is an enamelled figure of St Andrew bearing his cross, with rays of gold surrounding him in the form of a glory; it is suspended from the collar.
*The Mantle is a green velvet coat, with a representation of the Star of the Order on the left shoulder.
* The Hat is of black velvet and is plumed with white osprey feathers.

On other occasions, simpler insignia are worn: *The Badge is two-sided and worn (at the right hip) on a green ribbon passing over the left shoulder. On one side is the image of St Andrew bearing his cross. On the other side is an image of a green Thistle upon a green field, surrounded by the motto of the Order.
* The Star is worn on the left breast. It a silver figure of St Andrew's cross, with a ray emerging from each angle of the cross. In the centre is a gold field, upon which is a representation of a green Thistle, which is surrounded with a green circle bearing the motto Nemo me impune lacessit ('No one provokes me with impunity') in gold letters.