Born on August 21

1165 Philip II of France a Capetian King of France who reigned from 1180 to 1223, and the first to be called by that title. His predecessors had been known as kings of the Franks but from 1190 onward Philip styled himself king of France. The son of Louis VII and of his third wife, Adela of Champagne, he was originally nicknamed "God-given" because he was the first son of Louis VII and born late in his father's life
1229 Iwo Odrowąż a medieval Polish humanist, statesman, and bishop.
1535 Shimazu Yoshihiro the second son of Shimazu Takahisa and younger brother of Shimazu Yoshihisa. It had traditionally been believed that he became the seventeenth head of the Shimazu clan after Yoshihisa, but it is currently believed that he let Yoshihisa keep his position
1567 Francis de Sales C.O., O.M., O.F.M. Cap. was a Bishop of Geneva and is honored as a saint in the Roman Catholic Church. He became noted for his deep faith and his gentle approach to the religious divisions in his land resulting from the Protestant Reformation. He is known also for his writings on the topic of spiritual direction and spiritual formation, particularly the Introduction to the Devout Life and the Treatise on the Love of God
1579 Henri Duke of Rohan a French soldier, writer and leader of the Huguenots.
1583 Eleanor of Prussia a princess of the Duchy of Prussia by birth and Electress of Brandenburg by marriage.
1583 Denis Pétau a French Jesuit theologian.
1597 Roger Twysden an English historian and politician who sat in the House of Commons at various times between 1625 and 1640.
1643 Afonso VI of Portugal King of Portugal and the Algarves, the second of the House of Braganza, known as "the Victorious".
1660 Hubert Gautier a French engineer. He was born in Nîmes, France
1665 Giacomo F. Maraldi a French-Italian astronomer and mathematician. His name is also given as Jacques Philippe Maraldi. Born in Perinaldo he was the nephew of Giovanni Cassini, and worked most of his life at the Paris Observatory. He also is the uncle of Jean-Dominique Maraldi
1670 James FitzJames 1st Duke of Berwick an Anglo-French military leader, illegitimate son of King James II of England by Arabella Churchill, sister of the 1st Duke of Marlborough.
1681 Ernest Frederick I Duke of Saxe-Hildburghausen a duke of Saxe-Hildburghausen.
1698 Giuseppe Guarneri an Italian luthier from the Guarneri family of Cremona. He rivals Antonio Stradivari with regard to the respect and reverence accorded his instruments, and he has been called the finest violin maker of the Amati line. Instruments made by Guarneri are often referred to as Josephs or del Gesùs
1704 Johann Georg Chevalier de Saxe a Saxon Field Marshal and Governor of Dresden.
1709 Frederick Henry Margrave of Brandenburg-Schwedt the last owner of the Prussian secundogeniture of Brandenburg-Schwedt. His father was Margrave Philip William; his mother was Charlotte Johanna, a daughter of Prince John George II of Anhalt-Dessau and Princess Henriette Catherine of Nassau
1725 Jean-Baptiste Greuze a French painter.
1735 Tobias Furneaux an English navigator and Royal Navy officer, who accompanied James Cook on his second voyage of exploration. He was the first man to circumnavigate the world in both directions, and later commanded a British vessel during the American Revolutionary War
1747 Franz von Paula Schrank a German priest, botanist and entomologist.
1752 Jacques Roux a radical Roman Catholic priest that took an active role in the revolutionary politics during the French Revolution. He skillfully expounded the ideals of popular democracy and classless society to crowds of Parisian sans-culottes, working class wage earners and shopkeepers, radicalizing them into a dangerous revolutionary force. He became a leader of a popular far-left political faction known as the Enragés , and in 1791 he was elected to the Paris Commune
1754 Banastre Tarleton a British soldier and politician.
1754 William Murdoch a Scottish engineer and long-term inventor.
1757 Gustaf von Paykull a Swedish friherre and hovmarskalk , ornithologist and entomologist.
1765 William IV of the United Kingdom King of the United Kingdom of Great Britain and Ireland and of Hanover from 26 June 1830 until his death. William, the third son of George III and younger brother and successor to George IV, was the last king and penultimate monarch of Britain's House of Hanover
1780 Jernej Kopitar a Slovene linguist and philologist working in Vienna. He also worked as the Imperial censor for Slovene literature in Vienna. He is perhaps best known for his role in the Serbian language reform started by Vuk Stefanović Karadžić, where he played a vital role in supporting the reform by using his reputation and influence as a Slavic philologist
1785 George Bishop (astronomer) a noted English astronomer of the nineteenth century.
1789 Augustin-Louis Cauchy reputed to be an early pioneer of analysis. He started the project of formulating and proving the theorems of calculus in a rigorous manner, rejecting the heuristic principle of the generality of algebra exploited by earlier authors. He almost singlehandedly founded complex analysis and initiated the study of permutation groups in abstract algebra. A profound mathematician, Cauchy exercised a great influence over his contemporaries and successors. His writings cover the entire range of mathematics and mathematical physics
1792 Pyotr Pletnyov a minor Russian poet and literary critic, who rose to become the dean of the Saint Petersburg University and academician of the Petersburg Academy of Sciences.
1793 Christian Friedrich Hornschuch a German botanist born in Rodach, Bavaria.
1793 Princess Dorothea of Courland a Baltic German noblewoman. Her mother was Dorothea von Medem, Duchess of Courland, and although her mother's husband, Duke Peter von Biron, acknowledged her as his own, her true father might be Polish statesman Aleksander Batowski, thus making her half-Polish. For a long time, she accompanied the French statesman Charles Maurice de Talleyrand-Périgord, whereas she was the separated wife of his nephew, Edmond de Talleyrand-Périgord
1793 Henri Patin a French writer and translator from ancient Greek and Latin.
1794 Vasily Berkov a Russian shipbuilder and from 1829-1870 Director of the Admiralty Shipyard of Saint Petersburg, possibly in the rank of Counter-Admiral. Berkov deserves special credit for his translations of West-European literature on shipbuilding, into the Russian language. He was one of the so-called Rusluie, a Dutch community in 18th and 19th century Saint Petersburg, most of whose members originated from Vriezenveen
1796 Asher Brown Durand an American painter of the Hudson River School.
1798 Jules Michelet a French historian. He was born in Paris to a family with Huguenot traditions
1800 Hiram Walden a United States Representative from New York.
1801 Guillaume Groen van Prinsterer born at Voorburg, near the Hague.
1805 August Bournonville a Danish ballet master and choreographer. He was the son of Antoine Bournonville, a dancer and choreographer trained under the French choreographer, Jean Georges Noverre, and the nephew of Julie Alix de la Fay, née Bournonville, of the Royal Swedish Ballet
1813 Jean Stas a Belgian analytical chemist.
1814 Marie Gabriel Augustin Savard a French composer and teacher.
1815 Gustave-Adolphe Hirn a French physicist, astronomer. mathematician and engineer who made important measurements of the mechanical equivalent of heat and contributions to the early development of thermodynamics. He further applied his science in the practical development of steam engines
1816 Charles Frédéric Gerhardt a French chemist.
1821 William Barksdale a lawyer, newspaper editor, U.S. Congressman, and a Confederate general in the American Civil War. A staunch secessionist, he was mortally wounded during the Battle of Gettysburg while leading his brigade's attack on Union forces not far from Cemetery Ridge
1821 Andrew Kim Taegon the patron saint of Korea. In the late 18th century, Roman Catholicism began to take root slowly in Korea and was introduced by laypeople. In 1836 Korea saw its first consecrated missionaries arrive, only to find out that the people there were already practicing Catholicism
1826 Karl Gegenbaur a German anatomist and professor who demonstrated that the field of comparative anatomy offers important evidence supporting of the theory of evolution. As a professor of anatomy at the University of Jena and at the University of Heidelberg , Carl Gegenbaur was a strong supporter of Charles Darwin's theory of organic evolution, having taught and worked, beginning in 1858, with Ernst Haeckel, 8 years his junior
1840 Ferdinand Hamer a Catholic missionary to China and bishop who was killed in the Boxer rebellion in China.
1843 Infanta Maria Anna of Portugal (1843–1884) a Portuguese infanta , the eldest surviving daughter of Queen Maria II of Portugal and her King consort Ferdinand II of Portugal, born Prince of Saxe-Coburg and Gotha.
1845 Andreas Frühwirth an Austrian friar of the Dominican Order. He was promoted to the rank of cardinal of the Catholic Church and served as the Major Penitentiary of Apostolic Penitentiary
1846 Étienne Bazeries a French military cryptanalyst active between 1890 and the First World War. He is best known for developing the "Bazeries Cylinder", an improved version of Thomas Jefferson's cipher cylinder. It was later refined into the US Army M-94 cipher device. Historian David Kahn describes him as "the great pragmatist of cryptology. His theoretical contributions are negligible, but he was one of the greatest natural cryptanalysts the science has seen."
1848 Paul Henry and Prosper Henry Paul-Pierre Henry and his brother Prosper-Mathieu Henry were French opticians and astronomers.
1850 Ludwik Rydygier a Polish surgeon.