Druids 

Some say that the Druids were also Guardians of the Great Secret. (See "The Templar Pirates" page 36)

It is said that the word 'druid' signifies magicians. In Anglo-Saxon the word 'dry' means magician and the word 'drycroft' means magic. (See "The History of Freemasonry" by Mackey page 201)

Some say that the Druids worshiped the Sun, that Glorious Orb that opens and rules the Day, and provides the Earth and Mankind with the Solar energy needed for life.

Some say that the supreme god of the Druids was called Hu. 

Some say that the Druids started Freemasonry, or that Freemasonry at least incorporates a lot of the Druid's ideas into its ritual.  Similarities exist.  (See "The Origin of Free-Masonry" by Thomas Paine for more information.) (Also see MPD_0041)

Some say that the Druids practiced tree and serpent worship.

Some say that the Druids practiced Arkite worship, or worship of story of Noah and the ark.  It is said that their rituals centered around the deluge and the destruction and rebirth caused by the flooding.  (See "The History of Freemasonry" by Mackey page 207)

Some think that the Druids descended from the Buddhists and that they came to Britain with the great tide of emigration from Asia that also brought the Aryan race westward into Europe. (See "The History of Freemasonry" by Mackey page 208)

The deluge might represent the great cleansing by water that may have led to the practice of Lustration or Baptism.

Druidism existed in Britain and Gaul.  More is known about the Druids of Gaul that about the Druids of Britain. (See MPD_0041)

The Druids are thought by some to have built Stonehenge, but others do not agree.

The Druids of the British Isles presided over and directed the education of the youth, decided without appeal all judicial controversies, were exempt from all taxes and legal impositions.  They also imposed excommunication (As do the Amish and the Catholic Church) on those who refused to submit to their decisions on any question. (See "The History of Freemasonry" by Mackey page 200)

Druidism is still in existence to this date.  I have actually met some practicing Druids in the SCA.   Interesting and intelligent group of people.  The Druids do not seem to need to kill people who do not worship as they choose to so do.  Freemasons also do not care what religion one follows and do not kill people over their religious beliefs. 

There is said to have been three levels of Druidism

1) Lowest level, or First Degree of Druidism, was the Vates or the Bards
2) Middle Level was the Prophets
3) Highest level was the Druids

All were under the chief authority of the Archdruid.

They held an annual meeting and also met on 4 times a year on the solstices and the equinoxes.

None of their doctrines or ceremonies were written in any common language but they did write using a cipher.  The cipher may have been characters from the Irish Ogum alphabet. (Kind of like the Freemasons not writing down the Ritual.)

Members were admitted in secret ceremonies and were forbidden to expose these secrets to the profane. (Sound similar?)

(See "The History of Freemasonry" by Mackey page 200)

Mackey assumes that Druidism is solely a product of the Britans.

The Druids may have gotten their start in ancient Egypt.