Question: Which Prince of Bismarcks EMS dispatch incited France to declare the Franco-Prussian War in July 1870

Context:
Franco-Prussian War
The Franco-Prussian War or Franco-German War (German: "Deutsch-Französischer Krieg" , French: "Guerre franco-allemande" ), often referred to in France as the War of 1870 (19 July 1870 – 10 May 1871), was a conflict between the Second French Empire of Napoleon III and the German states of the North German Confederation led by the Kingdom of Prussia.
 The conflict was caused by Prussian ambitions to extend German unification and French fears of the shift in the European balance of power that would result if the Prussians succeeded.
 Some historians argue that the Prussian chancellor Otto von Bismarck deliberately provoked a French attack in order to draw the independent southern German states—Baden, Württemberg, Bavaria and Hesse-Darmstadt—into an alliance with the North German Confederation dominated by Prussia, while others contend that Bismarck did not plan anything and merely exploited the circumstances as they unfolded.
Kashubian diaspora
The Kashubian diaspora resulted from the emigration of Kashubians, in two waves occurring in the second half of the 19th century.
 The majority of Kashubian emigrants settled in the United States; others emigrated to Canada and Brazil.
 An online genealogical project, "The Great Kashubian Migration," is devoted to tracking their settlement patterns.
 Their reasons for emigration varied.
 Until the Franco-Prussian War, Kashubians emigrated primarily for economic reasons.
 After the Franco-Prussian War and especially due to the Kulturkampf, Kashubian emigration accelerated as socio-political factors came into play.
 In his 1899 book, "Statystyka ludnosci kaszubskiej" ("Statistics of the Kashubian Population"), the Kashubophile linguist and sociologist Stefan Ramult estimated that 130,700 Kashubians were living in the Americas.
French ironclad Marengo
Marengo was a wooden-hulled, armored frigate of the "Océan" class , built for the French Navy in the mid to late 1860s.
 The ship was running her sea trials in July 1870 when the Franco-Prussian War began and was immediately placed in until after the war was over.
 "Marengo" participated in the French occupation of Tunisia in 1881 and was flagship of the Northern Squadron in 1891 when it made port visits in Britain and Russia.
 She was sold for scrap in 1896.
North German federal election, August 1867
Elections to the Reichstag of the North German Confederation were held on 31 August 1867, with run-off elections during the following weeks.
 The National Liberal Party continued to serve as the largest party, winning 81 seats.
 These were the first regular and last elections during the North German Confederation.
 In July 1870 the Reichstag members decided not to hold new elections during the Franco-Prussian war, in spite of the three-year period.
1870–71 Commemorative Medal
The 1870–71 Commemorative Medal (French: "Médaille Commémorative 1870–71" , Dutch: "Herinneringsmedaille 1870–71" ) was a Belgian campaign medal established by royal decree on 20 September 1911 and awarded to all members of the Belgian Army who were mobilized during the period from 15 July 1870 to 5 March 1871 during the Franco-Prussian War.
Ems Dispatch
The Ems Dispatch (French: "Dépêche d'Ems" , German: "Emser Depesche" ), sometimes called the Ems Telegram, incited France to declare the Franco-Prussian War in July 1870.
 The actual dispatch was an internal message from the Prussian King's vacationing site to Otto von Bismarck in Berlin, reporting demands made by the French ambassador; it was Bismarck's released statement to the press that became known as "Ems Dispatch".
 The name referred to Bad Ems, a resort spa east of Koblenz on the Lahn river, then situated in Hesse-Nassau, a new possession of Prussia.
Otto von Bismarck
Otto Eduard Leopold, Prince of Bismarck, Duke of Lauenburg (1 April 1815 – 30 July 1898), known as Otto von Bismarck (] ), was a conservative Prussian statesman who dominated German and European affairs from the 1860s until 1890.
 In the 1860s, he engineered a series of wars that unified the German states, deliberately excluding Austria, into a powerful German Empire under Prussian leadership.
 With that accomplished by 1871, he skillfully used balance of power diplomacy to maintain Germany's position in a Europe which, despite many disputes and war scares, remained at peace.
 For historian Eric Hobsbawm, it was Bismarck who "remained undisputed world champion at the game of multilateral diplomatic chess for almost twenty years after 1871, [and] devoted himself exclusively, and successfully, to maintaining peace between the powers".
 However, his annexation of Alsace-Lorraine gave new fuel to French nationalism and promoted Germanophobia in France.
 This helped set the stage for the First World War.
Prince Robert, Duke of Chartres
Prince Robert Philippe Louis Eugène Ferdinand of Orléans, Duke of Chartres (November 9, 1840 – December 5, 1910) was the son of Prince Ferdinand Philippe, Duke of Orléans and thus grandson of King Louis-Philippe of France.
 He fought for the Union in the American Civil War, and then for France in the 1870 Franco-Prussian War.
 In 1863 he married his cousin Princess Françoise of Orléans in Kingston upon Thames – she was the daughter of François, Prince of Joinville.
 In 1886, he was exiled from France.
Army of Châlons
The Army de Châlons (French: "Armée de Châlons (1870)" ) was a French military unit that fought during the Franco-Prussian War of 1870.
 Formed in the camp of Châlons on August 17, 1870 from elements of the Army of the Rhin (1870) (French: "" ) which the unit was issued from, the Army of Châlons was engaged in combats of Beaumont and Sedan while disappearing during the capitulation of September 2, 1870.
La Promenade (Renoir)
The forest was a popular landscape subject for nineteenth-century French artists, particularly the forest of Fontainebleau.
 Before Renoir, Claude Monet (1840–1926) painted "Bazille and Camille (Study for "Déjeuner sur l'Herbe")" (1865), showing a couple together in the forest.
 In 1869, Renoir and Monet spent time painting together at La Grenouillère.
 By 1870, Renoir was living in Louveciennes with his mother.
 Throughout this decade, the eighteenth-century rococo art movement was back in style and Renoir embraced it.
 France declared war against Germany on July 19, 1870, starting the Franco-Prussian War.
 Renoir was conscripted and served four months in the cavalry but never saw combat.

Answer: Otto Eduard Leopold