A Druid was a member of the priestly class among the celtic people of Ireland, Britain, Gaul and the Iron Age. They left no written information  on themselves, and the only evidence are description left by certain Greeks, Romans and various authors and artists. They are vivid and compelling, and also they are without exception controversial, problematic and without a doubt fallacious (Hutton, 2009). The druids played an important part in the pagan Celtic society. According to Julius Caesar  they were one of the two most important social group and were responsible to organize divinations, worship and sacrifices, and juridical procedures for Irish, Gaulish and British society. He also claims that they were exempt form military services and paying taxes and they also had the power to excommunicate people from religious festivals and making them outcasts (Mueller, 2012).   

The Celtic word Vates is continued in Irish faith mesning "prophet, seer", and gwawd meaning "scorn, satire" in Welsh. According to Ancient Greek writers Diodorus, Starbo,  and Poseidonius, the Vates were one of three classes of Celtic priesthood, the others being Bards and Druids. They had the roles of seers and performed sacrifices (human sacrifices) under the supervision of druids. Therefore, their role corresponded to   that of an Adhvaryu In Vedic Religion (Kernunnos, 2013).

In the medieval British and Gaelic culture, a Bard was a professional poet, employed by a patron such as a nobleman or monarch, to commemorate the patrons ancestors and to praise the patrons activities. The Bards were those who sang the songs recalling the tribal warriors deeds of bravery as well as the family histories of the ruling strata of Celtic societies (Wikipedia, 2013).