In 1924, Louis de Broglie proposed that all particles behave to an extent like waves.

* 1706 – Louis de Cahusac, French playwright and librettist, and Freemason ( d. 1759 )

* 1644 – Louise de La Vallière, French mistress of Louis XIV of France ( d. 1710 )

de Pompadour, Louis XV's mistress, who was considered the most powerful woman in France at the time.

* 1779 – Louis de Freycinet, French explorer ( d. 1842 )

* 1892 – Louis de Broglie, French physicist, Nobel Prize laureate ( d. 1987 )

* 1767 – Louis Antoine de Saint-Just, French military leader and politician ( d. 1794 )

** Louis de Montfort

In 1752, the French astronomer Nicolas Louis de Lacaille subdivided it into Carina ( the keel, or the hull, of the ship ), Puppis ( the poop deck, or stern ), and Vela ( the sails ).

Antlia was created in 1756 by the French astronomer Abbé Nicolas Louis de Lacaille, who created fourteen constellations for the southern sky to fill some faint regions.

De Amore was written at the request of Marie de Champagne, daughter of King Louis VII of France and of Eleanor of Aquitaine.

Louis de Wohl worked as an astrologer for the British intelligence agency MI5, after it was claimed that Hitler used astrology to time his actions.

* 1713 – Louis, 4th duc de Noailles, French peer and Marshal of France ( d. 1793 )

* Schmidt, Hanns Peter: The Origin of Ahimsa, in: Mélanges d ' Indianisme à la mémoire de Louis Renou, Paris 1968

Toward the latter half of the 17th century, Louis XIV founded his ' Académie Royale de Musique et de Danse ', where specific rules for the execution of every dance and the " five positions " of the feet were formulated for the first time by members of the Académie.

After the French chemists Louis Nicolas Vauquelin, Louis Jacques Thénard, and Joseph-Louis Gay-Lussac approved the experiments of the young pharmacist Balard, the results were presented at a lecture of the Académie des Sciences and published in Annales de Chimie et Physique.

" Approval from Louis arrived on 27 June: Tallard was to reinforce Marsin and the Elector on the Danube via the Black Forest, with 40 battalions and 50 squadrons ; Villeroi was to pin down the Allies defending the Lines of Stollhofen, or, if the Allies should move all their forces to the Danube, he was to join with Marshal Tallard ; and General de Coignies with 8, 000 men, would protect Alsace.

* Louis de Blois ( 1506 – 66 )

In addition to Bonaparte himself, Louis Alexandre Berthier, Auguste de Marmont, Jean Lannes, Joachim Murat, Louis Desaix, Jean Reynier, Antoine-François Andréossy, Jean-Andoche Junot, Louis-Nicolas Davout and Dumas were all passengers on the cramped Mediterranean crossing.

The Saint-Esprit church was part of a bigger complex built by Louis XI to care for pilgrims to Santiago de Compostela.

* http :// www. chateaudevayres. com / home. html In French and English, with views of the Castle by Louis de Foix, the 16th century French Engineer who deviated the River Adour near Bayonne.

A costume design for Louis XIV as The Rising Sun, from the final entrée of Le Ballet de la Nuit ( 1653 ).

Saint Denis Basilica-( From left clockwise ) Gisants Bertrand du Guesclin, Charles VI of France | Charles VI, Isabeau of Bavaria, Louis de Sancerre, Charles V of France | Charles V, Jeanne de Bourbon, Queen of France | Jeanne de Bourbon

* Louis de Sancerre, Count of Sancerre ( 1342 – 1402 ), Marshal of France in 1369

Under Louis Philippe, he lived quietly upon his estate of l ' Étang, near Sancerre, but in 1837 he took an active part in the discussion of a new treaty of commerce with the United States, and caused several pamphlets to be printed on the subject.

Louis de Bourbon, duc de Bourbon, duc de Montmorency ( 1668 – 1689 ) duc d ' Enghien ( 1689 – 1709 ), 6th Prince of Condé, comte de Sancerre ( 1709 – 1710 ), comte de Charolais ( 1709 ), was born at the Hôtel de Condé in Paris on 10 November 1668

In the 1230s, in order to settle with Alice, Theobald IV had to sell his overlordship over the counties of Blois, Sancerre, and Châteaudun to Louis IX of France.

A mansion was built on the ruins of the original Chateau de Sancerre in 1874 by Mlle de Crussol d ' Uzès in the style of Louis XII.

* Louis II de Sancerre, Count of Sancerre ( d. August 26, 1346 ) One of the few French nobles to penetrate the English front line at the Battle of Crécy.

* Louis de Sancerre, Marshal of France, Constable of France ( 1342 – 1402 ) Buried in Saint Denis Basilica near King Charles V.

* Stephen of Sancerre, Lord of Vailly ( d. 1390 in Tunis ) Died fighting the Moors under the command of Louis II de Bourbon, Duke of Bourbon ( 1337 – 1410 ).

* Count Louis of Sancerre, companion of explorer Sieur de la Salle, 1682.

* Louis Mairet, Commander of the Legion of Honor, Companion of the Order of Liberation ( 1916 – 1998 ) Parachutist with the Free French Squadron ; destroyed the bridge at Sancerre in World War II.

In 1341 Louis deserted Edward but came only temporarily to terms with Philip.

The Lords of Sanneck Castle were elevated to comital status by Emperor Louis IV in 1341 at Munich, and received the title Cylie or Cilli derived from name of the Celje Castle in Lower Styria.

* Louis, Count of Beaumont-le-Roger ( 1341 – 1372 ), married 1358 Maria de Lizarazu, married 1366 Joanna of Durazzo ( 1344 – 1387 )

* Louis ( 1341 – 1372 ), Count of Beaumont-le-Roger, married firstly Maria de Lizarazu and secondly Joanna, Duchess of Durazzo

* 1250 – Seventh Crusade: Ayyubids of Egypt capture King Louis IX of France in the Battle of Fariskur.

* 1902 – Louis Beel, Dutch politician, Prime Minister of the Netherlands ( d. 1977 )

* 1904 – The Louisiana Purchase Exposition World's Fair opens in St. Louis, Missouri.

* 1664 – Fran &# 231 ; ois Louis, Prince of Conti, French general ( d. 1709 )

* 1979 – A Provisional Irish Republican Army bomb kills British World War II admiral Louis Mountbatten and three others while they are boating on holiday in Sligo, Republic of Ireland.

* 1962 – Louis Lipps, American football player

* 1792 – King Louis XVI of France is formally arrested by the National Tribunal, and declared an enemy of the people.

* 1717 – Louis François, Prince of Conti ( d. 1776 )

* 1764 – Louis Baraguey d ' Hilliers, French general ( d. 1816 )

* 1920 – Louis Pauwels, French journalist and writer ( d. 1997 )

* 881 – Battle of Saucourt-en-Vimeu: Louis III of France defeats the Vikings, an event celebrated in the poem Ludwigslied.

* 1899 – Louis Chiron, Monegasque race car driver ( d. 1979 )

In the Battle of Abensberg on 19 – 20 April 1809, Napoleon gained a significant victory over the Austrians under Archduke Louis of Austria and General Johann von Hiller.

* 1903 – Louis Leakey, Kenyan-English archaeologist ( d. 1972 )

* 1978 – Louis Saha, French footballer

* 778 – Louis the Pious ( d. 840 )

* 1672 – Franco-Dutch War: Louis XIV of France invades the Netherlands.

* 1682 – Louis, Dauphin of France, Duke of Burgundy ( d. 1712 )

* 1624 – The president of Louis XIII of France's royal council is arrested, leaving Cardinal Richelieu in the role of the King's principal minister.

* 1839 – The French government announces that Louis Daguerre's photographic process is a gift " free to the world ".

* 1743 – Madame du Barry, French mistress of Louis XV of France ( d. 1793 )