Title: Margaret I of Denmark
Content:  recognition of her capabilities. Knut Gjerset calls her "the first great ruling queen in European history." The youngest daughter of King Valdemar IV of Denmark, Margaret was born at Søborg Castle. She was a practical, patient administrator and diplomat, albeit one of high aspirations and a strong will, who intended to unite Scandinavia forever into one single entity with the strength to resist and compete against the might of the Hanseatic League. With her husband, King Haakon VI of Norway, Margaret had a son, King Olaf II of Denmark, who died before her. She was ultimately succeeded by a grandnephew, Eric of Pomerania. Although Eric came of age in 1401, Margaret continued for the remaining 
Title: Margaret
Content: Margaret I of Denmark (1353–1412) ; Margrethe II of Denmark (born 1940) 
Title: Margaret of Denmark, Queen of Scotland
Content:  Margaret of Denmark (23 June 1456 – 14 July 1486) was Queen of Scotland from 1469 to 1486 by marriage to King James III. She was the daughter of Christian I, King of Denmark, Norway and Sweden, and Dorothea of Brandenburg.
Title: 1410s in Denmark
Content: 1412 ; October - Margaret I of Denmark, queen of Denmark, Norway and Sweden (born 1353) 1416 ; 19 October &ndash; Peder Jensen Lodehat, bishop and politician  
Title: Princess Margaret of Denmark
Content:  Princess Margaret was born on 17 September 1895, in Bernstorff Palace north of Copenhagen. She was the fifth child and only daughter of Prince Valdemar of Denmark, and his wife Princess Marie of Orléans. Her father was a younger son of King Christian IX of Denmark and Louise of Hesse-Kassel, and her mother was the eldest daughter of Prince Robert, Duke of Chartres and Princess Françoise of Orléans. Her parents' marriage was said to be a political match. Her parents had agreed beforehand that all their sons would be raised Lutheran, their father's creed, and all their daughters Roman Catholic, their mother's faith. She was therefore the first Danish princess since the Reformation raised a Roman Catholic. She was named for her mother's sister Princess Marguerite d'Orléans. Her mother died in 1909.
Title: Margaret I of Denmark
Content:  years of her life to be sole ruler in all but name. Her regency marked the beginning of a Dano-Norwegian union which was to last for more than four centuries. Some Norwegian and Swedish historians have criticized Margaret for favouring Denmark and being too autocratic, though she is generally thought to have been highly regarded in Norway and respected in Denmark and Sweden. She was painted in a negative light in contemporary religious chronicles, as she had no qualms suppressing the Church to promote royal power. Margaret is known in Denmark as "Margrethe I" to distinguish her from the current queen, who chose to be known as Margrethe II in recognition of her predecessor.
Title: Kalmar Union
Content:  The union was the work of Scandinavian aristocracy wishing to counter the influence of the Hanseatic League. More personally, it was achieved by Queen Margaret I of Denmark (1353–1412). She was a daughter of King Valdemar IV and had married King Haakon VI of Norway and Sweden, who was the son of King Magnus IV of Sweden, Norway and Scania. Margaret succeeded in having her son Olaf recognized as heir to the throne of Denmark. In 1376 Olaf inherited the crown of Denmark from his maternal grandfather as King Olaf II, with his mother as guardian; when Haakon VI died in 1380, Olaf also inherited the crown of Norway. Margaret became regent of Denmark and Norway when Olaf died in 1387, leaving her without an heir. She adopted her great-nephew Eric of Pomerania the same year. The following year, 1388, Swedish nobles called 
Title: Margrethe
Content: Margrete or Margaret I of Denmark (1353–1412), Queen of Denmark and Queen of Norway and Sweden by marriage ; Margrethe II of Denmark (born 1940), queen regnant of Denmark ; Margaret of Sweden, Queen of Norway (c. 1155–1209), in Norwegian "Margrete", queen consort of Norway ; Margaret Skulesdatter (1208–1270), in Old Norse "Margrét", queen consort of Haakon IV of Norway ; Princess Margaret of Denmark (1895–1992), in Danish "Margrethe" ; Margrete Auken (born 1945), Danish politician ; Margrete Aamot Øverland (1913–1978), journalist and member of the Norwegian Resistance during World War II ; Margrethe Christiansen (1895–1971), Danish folk high school teacher ; Margrethe Lasson (1659–1758), first novelist in Denmark ; Margrethe Munthe (1860–1931), Norwegian teacher, children's writer, songwriter and playwright ; Margrethe Schall (1775–1852), Danish ballerina ; Margrethe Schanne (1921–2014), Danish ballerina ; Margrethe Vestager (born 1968), Danish politician Margret(h)e is an alternate spelling of the feminine given name Margaret. People so named include:
Title: Margrethe II of Denmark
Content:  Margrethe II (Margrethe Alexandrine Þórhildur Ingrid, born 16 April 1940) is Queen of Denmark and commander-in-chief of the Danish Defence. Born into the House of Glücksburg, Margrethe is the eldest child of Frederick IX of Denmark and Ingrid of Sweden. She became heir presumptive to her father in 1953, when a constitutional amendment allowed women to inherit the throne. Margrethe succeeded her father upon his death on 14 January 1972. On her accession, she became the first female monarch of Denmark since Margrethe I, ruler of the Scandinavian kingdoms in 1375–1412 during the Kalmar Union. In 1967, she married Henri de Laborde de Monpezat, with whom she had two 
Title: Margaret I of Denmark
Content:  to her as the "Lady Queen", without specifying what she was queen of, but not so Pope Boniface IX, who in his letters styled her "our beloved daughter in Christ, Margaret, most excellent queen of Denmark, Sweden and Norway". ("Carissime in Christo filie Margarete Dacie Suecie et Norwegie regine illustri".) When she married Haakon VI of Norway in 1363, he was co-King of Sweden, making Margaret queen consort, and despite being deposed, they never relinquished the title. In theory, the Swedes' expulsion of Albert I in 1389 simply restored Margaret to her original position. From 24 February 1389 to 28 October 1412, she was Queen of Denmark, Norway and Sweden and founder of the Kalmar Union, which united the Scandinavian countries for over a century. She acted as queen regnant of Denmark, although in those days it was not the Danish custom for a woman to reign.

Question: Who is the mother of Margaret I of Denmark?
Answer: Helvig of Schleswig.