Question: What is the birthdate of this Anglo-Irish soldier and statesman who was one of the leading military and political figures of the 19th-century Britain, and for which Jean Victor de Constant Rebecque countermanded the order of him to evacuate Dutch troops? 

Context paragraphs:
Jean d'Estournelles de Constant: Louis Etienne Jean Léonce Balluet d'Estournelles de Constant Rebecque (15 September 1859 – 31 July 1949) was a sailor from France, who represented his country at the 1900 Summer Olympics in Meulan, France.  Jean d'Estournelles de Constant as helmsman, took the 5th place in first race of the 0.5 to 1 ton and did not finished in the second race.  He did this with the boat "Pierre et Jean".

Mir 'Ali Mardan Khan, Nuzrat ol-Molk: Mir 'Ali Mardan Shah, Nuzrat ol-Molk (1840 – 1903) was a prominent Persian ruler and one of the leading military and political figures of 19th-century Persia.  His defeat of Turkomans and Afghans in 1868 put him in the top rank of Persia's military heroes.

David-Louis Constant de Rebecque: David-Louis, Baron de Constant de Rebecque, seigneur d'Hermenches and Villars-Mendraz, a.k.a. David-Louis Constant d'Hermenches (17 November 1722 in Lausanne – 25 February 1785 in Paris) was a colonel and commandant of a Swiss regiment in the Dutch Republic and Maréchal de camp in French service with Swiss regiments.  He is also known for his contact with Voltaire and his correspondence with Isabelle de Charrière.

Constant de Rebecque: The house of de Constant de Rebecque is an old family belonging to the Dutch nobility.  It originates from the Artois of region France where it was founded by brothers Ott and Hugues de Rebecque in the 11th century.

Robert Marie Jean Victor de Chevigny: Robert Marie Jean Victor de Boissonneaux de Chevigny (2 August 1920 – 11 June 2011) was a French bishop of the Roman Catholic Church.

Étienne Heudelet de Bierre: Étienne Heudelet de Bierre (12 November 1770 – 20 April 1857) joined the French army as a volunteer lieutenant in 1792.  A year later he became a staff officer for a number of generals before becoming Laurent Gouvion Saint-Cyr's chief of staff in 1795.  He fought under Jean Victor Marie Moreau in the 1796 campaign and fought at Kehl.  He became a general officer in 1799, leading his troops at the First and Second Battles of Zurich.  In April 1800 he was a brigade commander in Jean Victor Tharreau's division in Moreau's army.  In December of that year he fought at Hohenlinden under Michel Ney.

Jean Maspero: Jean Maspero (20 December 1885 – 17 February 1915) was an early 20th-century French papyrologist.  He was the son of egyptologist Gaston Maspero and his wife "née" Louise d'Estournelles de Constant (Sister of Paul d'Estournel de Constant, 1909 Nobel Peace Prize), and brother of Henri and Georges Maspero.

Jean Victor de Constant Rebecque: Jean Victor baron de Constant Rebecque (22 September 1773 – 12 June 1850) was a Swiss lieutenant-general in Dutch service of French ancestry.  As chief-of-staff of the Netherlands Mobile Army he countermanded the order of the Duke of Wellington to evacuate Dutch troops from Quatre Bras on the eve of the Battle of Quatre Bras, thereby preventing Marshal Michel Ney from occupying that strategic crossroads.

Paul-Henri-Benjamin d'Estournelles de Constant: Paul-Henri-Benjamin Balluet d'Estournelles, Baron de Constant de Rebecque (22 November 1852 – 15 May 1924), was a French diplomat and politician, advocate of international arbitration and winner of the 1909 Nobel Prize for Peace.

Arthur Wellesley, 1st Duke of Wellington: Field Marshal Arthur Wellesley, 1st Duke of Wellington, {'1': ", '2': ", '3': ", '4': "} (1 May 1769 – 14 September 1852) was an Anglo-Irish soldier and statesman who was one of the leading military and political figures of 19th-century Britain.  His defeat of Napoleon at the Battle of Waterloo in 1815 put him in the first rank of Britain's military heroes.

Supporting paragraphs: Jean Victor de Constant Rebecque Arthur Wellesley, 1st Duke of Wellington
Answer: 1 May 1769