Fleur-de-lis
The fleur-de-lis is a heraldic and decorative symbol representing a stylization of a flower, commonly associated with the lily or iris. It is known for its three-petal symmetrical design and is often associated with monarchy and nobility, especially in France.
Fleur-de-lis as an heraldic simbol
As a heraldic symbol, the fleur-de-lis dates back to the 12th century. It is known with certainty to have been first adopted as a semis on a field by the French king Philip II (1180-1214), and possibly even earlier by his father Louis VII (1137-80). At the very least, the arms “azure, a semis of fleur-de-lis or” are associated with French kings from the year 1200.
Fleur-de-lis as emblem
The fleur-de-lis, as an emblem, appears on coins and seals dating back to at least the 10th century.
Typically, it adorns the end of a scepter, decorates the edge of a crown, or is held oversized by the king alongside a scepter.
Thus, by the 11th and 12th centuries, there was a strong association with royal sovereignty. In fact, coins from Emperor Frederick I depict him holding such a scepter. Additionally, assuming it was already referred to as a fleur-de-lis at that time, the lily flower had significant religious connotations, particularly with the Virgin Mary, and later (in the 14th century) with the Trinity.
Other sources related to fleur-de-lis
There is an excellent source in this page, which discuses the heraldic significante related to the fleur-de-lis