Saint Brigid of Kildare, or nicknamed Mary of the Gael (Naomh Bríd) (c. 451–525) She is one of Ireland's three main patron Saints; along with Sts. Patrick and Colmcille
'One of the more commonly told stories of St. Brigid was when she went to the King of Leinster to ask for land to build a convent. She told the king that the place where she stood was the perfect place for a convent. It was beside a forest where they could collect firewood and berries. There was also a lake nearby that would provide water and the land was fertile. The king laughed at her and refused to give her any land. Brigid prayed to God and asked him to soften the king’s heart. Then she smiled at the king and said “will you give me as much land as my cloak will cover?” The king thought that she was joking and because Brigid’s cloak was so small he knew that it would only cover a very small piece of land. The king agreed and Brigid spread her cloak on the ground. She asked her four friends to hold a corner of the cloak and walk in opposite directions. The four friends walked north, south, east and west. The cloak grew immediately and began to cover many acres of land. The king was astonished and he realized that she had been blessed by God. The king fell to the ground and knelt before Brigid and promised her and her friends money, food and supplies...'
(Taken from Wikipedia)
Brigid also gives us her famous 'cross' made out of straw and is as associated with her as shamrock is with St. Patrick.
Her feast day is February 1st.