There are many different faerie organizations. Each has its own hierarchy and local legends.
Fairies can also be divided into the Seelie court and the Unseelie court.
The great Tuatha de Danann of Ireland flead to Tir Nan Og after their defeat by the Milesians, however those who remained in Ireland became the Daoine Sidhe.
Whales has perhaps more clans of faeries than any other area. In Glastonburry Tor, famous from Arturian legends, Gwyn ap Nudd rules over the Plant Annwn (roughly- family of hades).
Brittany has several classes of Faeries, the most popular being the Korrigans who have been counted to be more than 10 000 in the past.