Margaret of Denmark, died 1341, was a medieavel swedish queen known as queen Martha.
She was daughter of king Eric V of Denmark and Agnes of Brandenburg and sister of king Eric VI and was married to king Birger of Sweden in 1298; two years before, her brother had been married to her husbands sister, princess Ingeborg of Sweden.
Queen Martha was influenciall on her husband and participated in all the intrigues of his court. In swedish history, she had a quite bloodthirsty reputation; in the second of her husbands controversy with his brothers the dukes - the king and queen had during the first one been captured and imprisoned by them - the royal couple invited the dukes to great festivities, during wich the dukes vere captured and imprisoned and left to starve to death. The festivitys is described in a famous medieavel song; " Everyone danced all the way from indoors to outdoors, the queen had never looked so happy before."
When her husband was deposed in 1318, she fled home to her brother in Denmark, were she spent the rest of her life.