Question: Who was the grandfather of the seventh King of the Belgians?

Context articles: Order of the African Star
Philippe of Belgium
Fulco Ruffo di Calabria
Jeong of Balhae
King Albert Medal
Bagyidaw
Prince of Liège
Duke Pius August in Bavaria
Royal Order of the Lion
Sindae of Goguryeo

The Order of the African Star (Dutch: "Orde van de Afrikaanse Ster" , French: "Ordre de l'Étoile africaine" ) was established by King Leopold II of the Belgians on 30 December 1888, in his capacity as ruler of the Congo Free State, and was awarded for services to Congo and for the "promotion of African civilisation in general".
 It was incorporated into the Belgian honours system on 10 October 1908 following the annexation of the Congo Free State by Belgium.
 The motto of the Order is ""Travail et progrès"" (French: "Labour and progress" ).
 The King of the Belgians is its Grand Master.
 Even though Congo is no longer a Belgian colony, it is still considered to be a Belgian Order.
Philippe (] , French: "Philippe Léopold Louis Marie" , Dutch: "Filip Leopold Lodewijk Maria" , German: "Philipp Leopold Ludwig Maria" ; born 15 April 1960) is the seventh King of the Belgians, having ascended the throne on 21 July 2013, following his father's abdication.
 He is the eldest child of King Albert II, whom he succeeded upon Albert's abdication for health reasons, and Queen Paola.
 He married Countess Mathilde d'Udekem d'Acoz (now Queen Mathilde), with whom he has four children.
 King Philippe's elder daughter, Princess Elisabeth, is first in the line of succession.
Fulco VIII, Prince Ruffo di Calabria, 6th Duke of Guardia Lombarda (Naples 12 August 1884 – Ronchi di Apuana 23 August 1946) was an Italian World War I flying ace, senator under the fascist regime of Benito Mussolini in World War II for which he was convicted.
 He was also posthumous father-in-law of King Albert II of the Belgians, and grandfather of King Philippe of Belgium.
Jeong of Balhae (died 812?)
 (r. 809–812?)
 was the seventh king of Balhae.
 He was the son of King Gang.
 Little is known of his reign, save that he chose the era name "Yeongdeok" (永德, "eternal virtue").
 After his death, his brother succeeded him as King Hui.
The King Albert Medal (Dutch: "Koning Albert Medaille" , French: "Médaille du Roi Albert" ) was a Belgian medal established by royal decree on 7 April 1919 and awarded to both Belgians and foreigners who were exceptionally meritorious in promoting, organising or administering humanitarian and charitable work that assisted Belgians in need during the First World War.
Bagyidaw (Burmese: ဘကြီးတော် , ] ; also known as Sagaing Min, ] ; 23 July 1784 – 15 October 1846) was the seventh king of the Konbaung dynasty of Burma from 1819 until his abdication in 1837.
 Prince of Sagaing, as he was commonly known in his day, was selected as crown prince by his grandfather King Bodawpaya in 1808, and became king in 1819 after Bodawpaya's death.
 Bagyidaw moved the capital from Amarapura back to Ava in 1823.
Prince of Liège was a substantive title awarded by King Albert I of the Belgians to his youngest grandson, Prince Albert (former King Albert II), while he was third in line to the throne of Belgium.
 The title was used from 7 June 1934 until his accession as King of the Belgians in 9 August 1993.
 His wife, the present Queen Paola, was known as the Princess of Liège from their marriage in 1959 until 1993.
Duke "Pius August" in Bavaria, full German name: "Pius August Herzog in Bayern" (born 1 August 1786 in Landshut, Electorate of Bavaria; died 3 August 1837 in Bayreuth, Kingdom of Bavaria) was a Duke in Bavaria as a member of the Palatine Birkenfeld-Gelnhausen line of the House of Wittelsbach.
 Pius August was a grandfather of Empress Elisabeth of Austria through his son Duke Maximilian Joseph in Bavaria, as well as a great grandfather of Queen Elisabeth of the Belgians and an ancestor of the current generations of the Belgian and Italian Royal Families and the Grand Ducal Family of Luxembourg .
The Royal Order of the Lion (French: "Ordre Royal du Lion" ) (Dutch: "Orde van de Leeuw" ) was established by King Leopold II of the Belgians on 9 April 1891, in his capacity as ruler of the Congo Free State, and was awarded for services to Congo and its ruler that did not deserve the award of the Order of the African Star and were not necessarily performed from within the Congo.
 It was incorporated into the Belgian honours system following the annexation of the Congo Free State by Belgium.
 The motto of the Order is ""Travail et progrès"" (French: "Labour and progress" ).
 The King of the Belgians is its Grand Master.
 Even though Congo is no longer a Belgian colony, it is still considered to be a Belgian Order.
King Sindae of Goguryeo (89–179, r. 165–179) was the eighth ruler of Goguryeo, the northernmost of the Three Kingdoms of Korea.
 The Samguk Sagi records him as the half-brother of the sixth king Taejo and the seventh king Chadae.
 Other records indicate he may have been Taejo or Chaedae's son.