Jean Courtois called Sicily Herald was in the service of the king of the two Sicilies
Alfonso V of Aragon. He lived for a long time in
Mons in
Hainaut in the
Netherlands. At the beginning of his career, he was in the service of
Peter of Luxembourg, Count of Saint-Pol, and then he acted in the
Naples court of
Alfonso V of Aragon. In his work
Le Blason des Couleurs en armes, livrées, & devises (1414), Courtois developed a heraldic system consisting of the
tinctures, planets and
carbuncles, the virtues, metals, months, the zodiac, and weekdays among others. He claimed, his work was compiled with "the help of God (''l'Aide de Dieu
), princes, knights, squires and all his brothers, kings of arms and heralds". He was familiar with the Etymologies'' of
Isidore of Seville, and also he gave the names of the tinctures in Greek. However, his main contribution was the development of gemstone-planetary
blazon. == Editions ==