The present Danish Queen Margrethe II, traces her ancestry to Prince Christian of Glücksborg who ascended to the throne as Christian IX. He was the first monarch from the current House of Glücksborg after the extinction of the direct family lines coming from the ancient Danish dynasty – the House of Oldenborg. Frederick VII who was the last sovereign from the line died childless.
The way for the current House was opened by virtue of the Act of Succession of 1853. Prince Christian was a direct descendant of the Royal House. His was one of the longest reigns in the history of Denmark. Because his daughters got married to royalties from other countries, the Danish Royal House became directly related to many reigning Royal Houses in Europe such as Russia, Cumberland, Greece, and Norway. This earned for him the moniker “father-in-law of Europe”.
The then Princess Margrethe is the daughter of Frederik IX and Princess Ingrid of Sweden. Being the eldest daughter, she was proclaimed queen after her father died. Queen Margrethe became queen in 1972. The House of Glücksborg celebrated its 150th year last year 2013. This Dynasty is the youngest branch of the Danish Royal lines that comes from Gorm the Old and Queen Thyra.
The right to succession for women royalty was guaranteed by the Act of Succession of 1853. This explains why it was Queen Margrethe who ascended the throne. Since Denmark has a constitutional monarchy, the Queen cannot perform political acts independently. All Acts of Parliament that she signs will need to be countersigned by a Cabinet Minister.