The stone is believed to be half of the Stone of Scone which originally belonged to Scotland.
Scottish Kings were crowned over the stone, because it was believed to have special powers. One of the stories says that an old woman cast a spell on the stone to reward a king who had saved her from drowning. Kissing the stone while under the spell gave the king the ability to talk sweetly. He was able to talk anyone into doing things. The stone was given to Cormac McCarthy by Robert the Bruce in 1314 in return for his support in a battle.

Queen Elizabeth I wanted the Irish chiefs to agree to hold their own lands under title from her. Cormac Teige McCarthy, the Lord of Blarney, handled her every Royal wish with clever promises keeping loyalty to the Queen without "giving in". Elizabeth proclaimed that McCarthy was giving her "a lot of Blarney." This is how the story began that if you kiss the blarney stone you will also be able to make clever promises.