“Leinster; This is the Province named for the Solar Cult that governed there. Lein, is a derivation of the word Leo. Leo is the ancient name of the house and domicile of the sun. Leinster (Ireland), the place under the Lion, is famed for its stately houses and slightly more temperate weather. (See also the English Leister.) Some of the Semitic tribes that peopled the British Isles brought the symbol of the lion to these shores, particularly the Tribe of Dan, which is why there are so many place names beginning with the prefix Dan or Dun, in Celtic countries.”
Source: Astro-Theology Etymology and Sidereal Mythology Tarot Astronomy
Image: Flag of Leinster
Learn More: Linster, Ireland (Britannica)