The House of Schleswig-Holstein-Sonderburg-Glücksburg, also known by its short name as the House of Glücksburg, is the senior surviving branch of the German House of Oldenburg, one of Europe's oldest royal houses. Oldenburg house members have reigned at various times in Denmark, Norway, Sweden, Iceland, Greece, several northern German states, and Russia. It takes its name from the family seat in Glücksburg, a small town in Schleswig-Holstein, Germany.
Current monarch King Harald V, former monarch Queen Margrethe II and former consorts Queen Anne-Marie of Greece and Queen Sofia of Spain are patrilineal members of cadet branches of the House of Glücksburg.
The present senior member of the House of Oldenburg and the House of Glücksburg and traditional heir to the family's ancestral lands, including Glücksburg itself, is Friedrich Ferdinand, Prince of Schleswig-Holstein (born 1985), who heads the foundation that owns the family's ancestral seat, Glücksburg Castle.
thumb|[[Glücksburg Castle, with the Flensburg Firth (separating Denmark and Germany) in the background]]
Etymology
"House of Glücksburg" is the shortened form of "House of Schleswig-Holstein-Sonderburg-Glücksburg"a collateral branch of the House of Oldenburg. The house derives its name from two regions and two towns on the Jutland Peninsula.
The two regions of Schleswig and Holstein are divided by the Eider River. While Schleswig for centuries constituted the southernmost region of Denmark, Holstein historically has been the northernmost area within the Holy Roman Empire. The northern border of Holstein along the Eider had already formed the northern border of Francia and the Carolingian Empire, after Emperor Charlemagne upon the Saxon Wars reached an agreement with King Hemming of Denmark in 811. The lands of Schleswig beyond the river remained a fief of the Danish Crown, while Holstein became an integral part of East Francia, the Kingdom of Germany and the Holy Roman Empire. Even earlier, the Eider had already been the border river between Saxons and Polabian Slavs to the south, and Danes and North Frisians to the north. This is evidenced in the largely Slavic-derived toponomy in Eastern Holstein, as opposed to the many Danish-derived place names in Schleswig including Southern Schleswig. Since the 1920 Schleswig plebiscites, Schleswig has been divided between Denmark (Northern Schleswig), and Germany (Southern Schleswig).
The town of Sønderborg—the German name of which is "Sonderburg"—is located on the northern shores of the Flensburg Firth in Denmark (Northern Schleswig), while Glücksburg lies on the southern shores of the firth in Germany (Southern Schleswig).
Since Glücksburg Castle is the ancestral seat of the house, the house is mostly shortened to just "House of Glücksburg". It is also spelled "House of Glücksborg" (the name of Glücksburg in the local Low German dialect) or "House of Lyksborg" (the Danish name of Glücksburg).
The literal translation of "Glücksburg" is "Luck Castle" (Glück = luck; Burg = castle).
History
thumb|left|250px|2 [[Danish rigsdaler|rigsdaler - death of Frederik VII and accession of Christian IX marking the transfer of the throne to the Glücksburg branch of the House of Oldenburg]]
Glücksburg is a small coastal town on the German southern side of the fjord of Flensburg that divides Germany from Denmark. Frederick suffixed the territorial designation to the ducal title he already held, in lieu of "Beck" (an estate the family had, in fact, sold in 1745).
|born 1968
|2024–present
|Count of Monpezat
|}
Greece
thumb|[[Coat of arms of the Kingdom of Greece|Coat of arms of the King of the Hellenes]]
thumb|right|Thirty-[[Modern drachma|drachma coin of 1963, commemorating the centennial of the reign of the House of Glücksburg. Clockwise from the top: Paul, George II, Alexander, Constantine I and George I.]]
In 1863 and with the name George I, Prince Wilhelm of Denmark was elected King of the Hellenes on the recommendation of Europe's Great Powers. He was the second son of King Christian IX of Denmark.
{| class="wikitable"
|-
! Portrait !! Name !! Life !! Reign !! Additional titles
|-
| 100px
| George I
| 1845–1913
| 1863–1913
|
|-
| 100px
| Constantine I
| 1868–1923
|
|
|-
| 100px
| Alexander
| 1893–1920
| 1917–1920
|
|-
| 100px
| George II
| 1890–1947
|
|
|-
| 100px
| Paul
| 1901–1964
| 1947–1964
|
|-
| 100px
| Constantine II
| 1940–2023
| 1964–1973
|
|}
The Hellenic constitutional monarchy was usurped in a coup d'état by a military junta in 1967 and the royal family fled into exile. The monarchy was abolished in 1973. After the collapse of the military dictatorship in 1974, 69.18% of votes recorded in a republic referendum were against the restoration of the monarchy.
As of 2024, the family has assumed the last name "De Grèce" (; "of Greece"), first used by Greek author and dynast Prince Michael of Greece and Denmark for his pen name as Michel de Grèce, as the only one familiar to them.
Norway
thumb|[[Coat of arms of Norway|Coat of arms of the King of Norway]]
In 1905, Prince Carl of Denmark became Norway's first independent monarch in 518 years, taking the regnal name Haakon VII. His father was King Frederick VIII of Denmark, and one of his uncles was King George I of Greece.
{| class="wikitable"
|-
! Portrait !! Name !! Life !! Reign !! Additional titles
|-
|| 100px
|| Haakon VII
|| 1872–1957
|| 1905–1957
|| Prince of Denmark,<br />Prince of Schleswig-Holstein-Sonderburg-Glücksburg
|-
|| 100px
|| Olav V
|| 1903–1991
|| 1957–1991
|| Prince of Denmark,<br />Prince of Schleswig-Holstein-Sonderburg-Glücksburg,<br />Olympic Sailing Champion
|-
|| 100px
|| Harald V
|| born 1937
|| 1991–present
|| Prince of Schleswig-Holstein-Sonderburg-Glücksburg,<br />Sailing World Champion
|}
The heir apparent is Crown Prince Haakon of Norway (born 1973). See the present line of succession.
Iceland
thumb|[[Kingdom of Iceland]]
In 1918, Iceland was elevated from an autonomous Danish province to a separate Kingdom of Iceland. Christian X of Denmark was henceforth King of Denmark and Iceland until 1944, when Iceland dissolved the personal union between the two countries and became a republic.
{| class="wikitable"
|-
! Portrait !! Name !! Life !! Reign !! Additional titles
|-
|| 100px|Kristjàn X
|| Kristján X
|| 1870–1947
|| 1918–1944
||
|}
The heir apparent was his son, Frederik IX of Denmark (1899–1972).
United Kingdom
thumb|Arms of Prince Philip, Duke of EdinburghIn 1947, Philip Mountbatten married Princess Elizabeth (later Queen Elizabeth II). Born into the house of Glücksburg as a prince of Denmark and Greece, he later relinquished these titles and was made Duke of Edinburgh by his father-in-law, King George VI of the United Kingdom. In addition Philip took the surname "Mountbatten", an anglicized form of his mother's house name, Battenberg.
As all of his children were born after this change, the eldest born in 1948, the agnatic house of Charles III, Anne, Princess Royal, Andrew Mountbatten-Windsor, and Prince Edward, Duke of Edinburgh is Mountbatten, though the British royal family officially uses the House of Windsor, and the surname Mountbatten-Windsor.
{| class="wikitable"
|-
! Portrait !! Name !! Life !! Tenure !! Additional titles
|-
|| 100px
|| Prince Philip, Duke of Edinburgh