Engelbert-Maria von Arenberg (full name: Engelbert Prosper Ernst Maria Joseph Julius Balthasar Benedikt Anton Eleonore Lorenz; born August 10, 1872 in Salzburg; † January 15, 1949 in Lausanne) was a German nobleman and 9th Duke of the House of Arenberg. He was a grandson of Duke Prosper Ludwig von Arenberg (1785–1861), the sovereign of the Duchy of Arenberg-Meppen. His father, Engelbert-August (1824–1875), was the 8th Duke of the House of Arenberg. Engelbert Maria von Arenberg initially grew up in Belgium in the Egmont Palace in Brussels and in the Heverlee Palace near Leuven and Enghien Palace southwest of Brussels. From 1889 to 1893 he was an officer in the Prussian Army in the “von Driesen” (Westphalian) No. 4 Cuirassier Regiment in Münster and from 1893 to 1896 he served in the Guard Cuirassier Regiment in Berlin. After his father's death, Duke Engelbert-Maria inherited his father's extensive property, including extensive forest areas in Emsland. In 1903 he acquired Nordkirchen Castle in Münsterland.

The Belgian Royal Escort (Dutch: Koninklijk escorte te paard, French: Escorte royale à cheval) is a horse-mounted unit that accompanies the Belgian monarch on ceremonial occasions. It also provides escorts for foreign visiting heads of state and ambassadors presenting their credentials at the Royal Palace in Brussels. The Belgian monarchs have been accompanied by a mounted escort on state occasions since Belgium's independence in 1830. Until 1914 these were provided by detachments drawn from either the Marie-Henriette squadron of the Civic Guard of Brussels or from the Guides Regiments of the regular cavalry of the Belgian Army, based in Brussels. The full dress uniform of bearskin, black tunic and white breeches then adopted, and still worn, had been that of the mounted gendarmerie prior to 1914.

The House of Arenberg is an aristocratic lineage that is constituted by three successive families that took their name from Arenberg, a small territory of the Holy Roman Empire in the Eifel region.[a] The inheritance of the House of Croÿ-Aarschot made the Arenbergs the wealthiest and most influential noble family of the Habsburg Netherlands. The family's Duchy of Arenberg was mediatized in 1810. As such, the Arenbergs belong to the small group of families that constitute the Hochadel (German for 'high nobility'). In 1827 Prince Pierre d'Arenberg, third son of the 6th Duke of Arenberg, was made a Peer of France and his descendants are now a French branch of the family (French Dukes and Peers). During the War of the First Coalition, the House of Arenberg lost its territories on the Left Bank of the Rhine. In 1803, Louis Engelbert, 6th Duke of Arenberg, was compensated with Recklinghausen and Meppen in Germany, and in 1806 also with the county of Dülmen, together named the Duchy of Arenberg. In 1810, Napoleon occupied it; in