Margrethe II (born 16 April 1940) is Queen of Denmark and commander-in-chief of the Danish Defence. Since the death of Queen Elizabeth II of the United Kingdom on 8 September 2022, she is Europe's longest serving current head of state, having reigned as Denmark’s monarch for over 50 years, and the world's only current queen regnant. Born into the House of Glücksburg, a cadet branch of the House of Oldenburg, 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 sons: Crown Prince Frederik and Prince Joachim. Margrethe is known for her strong archaeological passion and has participated in several excavations, including in Italy, Egypt, Denmark and South America. She shared this interest with her grandfather Gustaf VI Adolf of Sweden, with whom she spent some time unearthing artefacts near Etruria in 1962.