Albert I of Belgium in the context of "Princess Marie of Hohenzollern-Sigmaringen"

Leopold II (9 April 1835 – 17 December 1909) was the second king of the Belgians from 1865 to 1909, and the founder and sole owner of the Congo Free State from 1885 to 1908.

Born in Brussels as the second but eldest-surviving son of King Leopold I and Queen Louise, Leopold succeeded his father to the Belgian throne in 1865 and reigned for 44 years until his death, the longest reign of a Belgian monarch to date. He died without surviving legitimate sons; the current king of the Belgians, Philippe, descends from his nephew and successor, Albert I. He is popularly referred to as the Builder King in Belgium in reference to the great number of buildings, urban projects and public works he commissioned.

The German occupation of Belgium (French: Occupation allemande, Dutch: Duitse bezetting) of World War I was a military occupation of Belgium by the forces of the German Empire between 1914 and 1918. Beginning in August 1914 with the invasion of neutral Belgium, the country was almost completely overrun by German troops before the winter of the same year as the Allied forces withdrew westwards. The Belgian government went into exile, while King Albert I and the Belgian Army continued to fight on a section of the Western Front. Under the German military, Belgium was divided into three separate administrative zones. The majority of the country fell within the General Government, a formal occupation administration ruled by a German general, while the others, closer to the front line, came under more repressive direct military rule.

The German occupation coincided with a widespread economic collapse in Belgium with shortages and widespread unemployment, but also with a religious revival. Relief organisations, which relied on foreign support to bring food and clothing to Belgian civilians, cut off from imports by the Allied naval blockade and the fighting, also became extremely important to the social and cultural life of the country.

Victor Pierre Horta (French: [viktɔʁ ɔʁta]; Victor, Baron Horta after 1932; 6 January 1861 – 8 September 1947) was a Belgian architect and designer, and one of the founders of the Art Nouveau movement. He was a fervent admirer of the French architectural theorist Eugène Viollet-le-Duc and his Hôtel Tassel in Brussels (1892–93), often considered the first Art Nouveau house, is based on the work of Viollet-le-Duc. The curving stylized vegetal forms that Horta used in turn influenced many others, including the French architect Hector Guimard, who used it in the first Art Nouveau apartment building he designed in Paris and in the entrances he designed for the Paris Metro. He is also considered a precursor of modern architecture for his open floor plans and his innovative use of iron, steel and glass.

Horta's later work moved away from Art Nouveau, and became more geometric and formal, with classical touches, such as columns. He made a highly original use of steel frames and skylights to bring light into the structures, open floor plans, and finely-designed decorative details. His later major works included the Maison du Peuple/Volkshuis (1895–1899), Brussels' Centre for Fine Arts (1923–1929) and Brussels-Central railway station (1913–1952). In 1932, King Albert I conferred on Horta the title of Baron for his services to the field of architecture.

The Battle of the Yser (French: Bataille de l'Yser, Dutch: Slag om de IJzer) was a battle of the First World War that took place in October 1914 between the towns of Nieuwpoort and Diksmuide, along a 35 km (22 mi) stretch of the Yser River and the Yperlee Canal, in Belgium. The front line was held by a large Belgian force, which halted the German advance in a costly defensive battle.

The victory at the Yser allowed Belgium to retain a small strip of territory, with Germany in control of 95 per cent of Belgian territory, which made King Albert a Belgian national hero, sustained national pride and provided a venue for commemorations of heroic sacrifice for the next hundred years.

William, Prince of Hohenzollern (German: Wilhelm August Karl Joseph Peter Ferdinand Benedikt Fürst von Hohenzollern) (7 March 1864 – 22 October 1927) was the eldest son of Leopold, Prince of Hohenzollern and Infanta Antónia of Portugal.

William was an older brother of Ferdinand of Romania. His first cousins included (among others) Carlos I of Portugal, Albert I of Belgium, Frederick Augustus III of Saxony, and Princess Maria Josepha of Saxony.

Elisabeth of Bavaria (Elisabeth Gabriele Valérie Marie; 25 July 1876 – 23 November 1965) was Queen of the Belgians from 23 December 1909 to 17 February 1934 as the wife of King Albert I, and a duchess in Bavaria by birth. She was the mother of King Leopold III of Belgium and of Queen Marie-José of Italy, and grandmother of kings Baudouin and Albert II of Belgium, the pretender Prince Vittorio of Italy as well as Grand Duchess Joséphine-Charlotte of Luxembourg