The swearing-in ceremony (; ) occurs when the Belgian heir-apparent or heir-presumptive takes the oath that allows him or her to become King or Queen regnant of the Belgians. Article 91 of the Belgian Constitution outlines this ceremony, which transpires no later then ten days after the death or abdication of the previous monarch, at the Palace of the Nation in Brussels, the seat of the Belgian Parliament. Should the monarch be unable to governThe words incapacité de régne (unable to rule) are used without further clarification in the Belgian constitution, and have been interpreted as mental, physical or even moral incapacity. for more than ten days, the same oath is taken by the regent appointed by the Chambers.Belgian Constitution, art. 92 to 95.

A significant and symbolic act in the Belgian constitutional monarchy system, the swearing-in of the oath distinguishes itself from the automatic successions of Ancien Régime monarchies. It conditions the accession of the sovereign to the throne. By accepting their constitutional mandate, the monarch becomes the Nation's delegate and can exercise the prerogatives devolved to them by the Constitution.

The date of Leopold I's swearing-in (21 July 1831) is marked annually by Belgian National Day, a public holiday, established by law on 27 May 1890. Cédric Istasse, "Histoire, mémoire et identité : les fêtes nationales, régionales et communautaires en Belgique", Courrier hebdomadaire du CRISP, 2019 (read online archive, accessed 15 January 2023).Viatour and De Groote 1899, p. 40.

History

Surlet de Chokier (regent)

Although not a royal oath, it is noteworthy to mention the inauguration of regent Érasme-Louis Surlet de Chokier on 25 February 1831, which took place at the Palace of the Nation in Brussels. The ceremony occurred in a grandiose setting with a sizable audience in attendance. Émile Ruyttens, Discussions du Congrès national de Belgique, vol. II, Brussels, Société Typographique belge, 1844 (read online archive), Séance solennelle tenue le vendredi 25 février 1831 pour l'installation du Régent, pp. 592-597. The regent, garbed in a modest black habit, was welcomed by a row of civic guards who bestowed him with his coat of arms. Standing on a platform, Louis de Lichtervelde, Le Congrès national: l'œuvre et les hommes, Brussels, 1945 (read online archive), "La crise de la révolution et de la régence". he took the constitutional oath and delivered a brief speech to a standing ovation.

Leopold I

Following this precedent, the first-ever royal oath-taking ceremony occurred in Belgian history on 21 July 1831, using a unique ceremonial that was not repeated for future investitures. Leopold of Saxe-Coburg and Gotha was elected as King of the Belgians under the name Leopold I, arriving in an unfamiliar country where the kingdom's regent and other members of the National Congress had already made preparations. For this significant occasion for the fledgling kingdom, the political authorities looked to the Joyous Entry of the former Dukes of Brabant and the investitures of the Netherlands (including that of the former King William I in BrusselsPirenne 1952, p. 23.) as well as the former Principality of Liège for inspiration. Consequently, unlike subsequent investitures, this ceremony was conducted in public."To make this pledge [of joyful entry] more solemn, it was an ancient custom to swear reciprocal oaths in the face of heaven. Thus, the inauguration of the Counts of Flanders took place on the Friday market in Ghent, and the Place Royale in Brussels was usually the scene of the inauguration of the Dukes of Brabant". Quoted in Théodore Juste, Histoire du Congrès national ou de la fondation de la monarchie belge, t. II, Librairie polytechnique d'Auguste Decq, 1850, p. 352.

Upon arriving in Brussels at daybreak through the , Nicolas Rouppe, the Burgomaster of Brussels, presented Leopold with the keys to the city; however, the king declined, saying "they couldn't be in better hands." Carlo Bronne, Léopold Ier et son temps, Bruxelles, Paul Legrain, 1990, p. 64. Leopold then proceeded to the Place Royale/Koningsplein in front of the Church of St. James on Coudenberg, where the remainder of the ceremony took place. "Le voyage de Léopold 1e de Londres jusqu’à sa prestation de serment en 5 jours" archive, on histoiresroyales.fr, 27 January 2021 (accessed 16 August 2021). A raised platform and a canopy, displaying the names of the Revolution's victories, had been set up. The ceremony took place in a crimson draped gallery where a large crowd of Congress members cheered enthusiastically. The event began at 1:15pm with the transfer of the regent's powers to Étienne de Gerlache, the president of the House of Representatives. Viscount Charles Vilain XIIII Paul Vaute, "De 1831 à 1993, sept serments jalonnent notre histoire", La Libre, 21 July 2013 (read online archive, accessed 21 January 2023). read 139 articles of the Constitution followed by the king taking the oath and giving a brief French speech. Étienne de Gerlache then proclaimed "" signaling the king's ascent to the throne.

Leopold II

Seven days following Leopold I's death, his oldest son Prince Leopold was sworn in as Leopold II on 17 December 1865. He arrived on horseback at the Palace of the Nation with his brother Philippe and received enthusiastic public praise.Pirenne 1952, p. 128. He then walked into an unadorned hemicycle. In accordance with the monarch's request, a ceremonial throne featuring armrests decorated with lions and a red velvet backrest inscribed with the national motto was positioned beneath a regal dais. Present in the audience were not only the parliamentary body, but also cabinet members, judges, high-ranking civil servants, the bishopric, and the diplomatic corps. Despite its ornamental nature, the throne held no practical significance. Georges-Henri Dumont, La vie quotidienne en Belgique sous Léopold II, Hachette, 1975, p. 7. The royal family, attired in mourning, sat in a separate gallery accompanied by a large number of aristocrats as per the sovereign's request."There is no question of the Queen sitting next to me in Parliament when I am sworn in. I intend to keep my throne separate from the podium where my family will be assembled". Quote from Jo Gérard, Le pharaon des Belges: Léopold II, Brussels, Jean-Marie Collet, 1984, p. 27.Among those present were King Louis I of Portugal, the Prince of Wales, the Duke of Connaught, Prince George of Saxony, the Prince Royal of Prussia, Prince Auguste of Saxe-Coburg, Prince Louis of Hesse, Archduke Joseph, the Prince of Baden, Prince Nicolas of Nassau, the Duke of Cambridge and Prince Leopold of Hohenzollern. List included in Louis de Lichtervelde, Léopold II, Louvain, Éditions Rex, 1933, L'avènement de Léopold II, p. 54. Upon delivering his speech and taking the oath, Jean Stengers, L'action du Roi en Belgique de 1831 à nos jours: Pouvoir et influence, Bruxelles, Racine, 2008, p. 176. the king and his son, the Duke of Brabant, emerged onto the balcony of the Royal Palace to observe a military parade on the Place des Palais/Paleizenplein. The ceremony was conducted amidst a joyful atmosphere of "indescribable enthusiasm."

Albert I

On 23 December 1909, just six days following the death of Leopold II, his nephew, Prince Albert, rode to the Palace of the Nation. In the same scene where his uncle had sworn in, he joined the royal family, who were already seated under their canopy.Pirenne 1952, p. 259. The monarch, for the first time, gave his oath in Dutch to emphasize the bilingual nature of the kingdom secured by the (). After receiving a standing ovation from parliamentarians, Workers' Party representatives attempted to interrupt the ceremony with shouts of "Long live universal suffrage!" (). However, the assembly quickly drowned out the disruptive voices with cheers of "Long live the king!" (). During his self-written speech, the new king expressed a desire to improve colonial policy by implementing a program worthy of the Congo. The next day, the royal couple attended a Te Deum ceremony at the Church of St. Michael and St. Gudula (now Brussels' cathedral).

Leopold III

Prince Leopold took his oath of office on 23 February 1934, six days following Albert I's fatal mountaineering accident. He rode on horseback alongside his brother Charles and was greeted by a cheering crowd as he made his way from the Palace of Laeken to the Palace of the Nation."Belgium: King Albert I laid to rest / Duke of Brabant take oath as King Leopold III" archive, on British pathe (Accessed 18 January 2023). Despite the sadness of his bereavement, he pronounced his oath without hesitation. Charles d'Ydewalle, "S.M. Léopold III: Roi des Belges", Revue des Deux Mondes, 1934 (read online archive, Accessed 15 January 2023). "Dans 'Le Soir' de 1934: Léopold III prête serment dans une Belgique sous le choc", Le Soir, 19 July 2019 (read online archive, Accessed 15 August 2021). Upon ascension to the throne, Leopold III paid his respects to the Unknown Soldier at the Congress Column: "Prestation de serment et discours du Roi Léopold III" (audio version) archive (Accessed 15 January 2023)].

Charles (regent)

In 1944, following the Liberation, King Leopold III was imprisoned by the Third Reich, hence unable to rule. Although the constitutional regulations allowed for the establishment of a regency beyond a ten-day interregnum, some republican parties endeavored to create a republic. Ultimately, after two rounds of voting, the king's younger brother, the Count of Flanders, was selected as the regent. On 21 September 1944, the ceremony took place in a straightforward environment adorned with the flags representing the Allied nations. Séance solennelle des Chambres réunies tenue le jeudi 21 septembre 1944 pour recevoir le serment constitutionnel de S.A.R. le prince Charles, Régent du Royaume (read online archive). The individual in question swiftly pledged to "," as he voiced it. Notably, this oath marked the first instance of taking a pledge while refraining from raising an outstretched arm – a gesture that bore a resemblance to the Roman salute implemented during Fascist rituals.

Baudouin

King Baudouin was sworn in twice. The first instance occurred on 11 August 1950, when Leopold III delegated his powers to his son to address the Royal Question. As a result, the son became the "Prince Royal," a special title equivalent to a de facto regency, "Régence: CRISP ASBL" archive, on vocabulairepolitique.be (Accessed 24 January 2023). as Leopold III aimed to prolong his abdication. During the ceremony, Communist parliamentarians led by Julien Lahaut launched the thunderous chant of "" in front of a visibly uncomfortable prince. Prestation de serment du Prince Baudouin, Journal Les Actualités françaises, 17 July 1951 read online archive. However, the cheers for the prince quickly drowned out the chant. Baudouin took his oath while disregarding the Republican outbursts. Gaston Eyskens, Mémoires, Bruxelles, Éditions du CRISP, 2012, p. 425. The second oath occurred on 17 July 1951, the day following King Leopold's abdication. The ceremonies were less extravagant than those of preceding monarchs, and foreign ambassadors and the royal family Jacques Pirenne, Mémoires et notes politiques, Verviers, André Gérard, 1975, p. 461 were absent as the events were not conducive to great family joy. Upon becoming king, Baudouin paid homage to the Unknown Soldier before appearing, solemn and alone, on the balcony of the royal palace:

Albert II