Born on August 12

652 Ségéne mac Fiachnaí the fifth abbot of the Iona Abbey in Scotland.
1222 Vladislaus III Duke of Bohemia the youngest son of Vladislaus II and younger brother of Ottokar On 22 June 1197, he was elected Duke of Bohemia. Faced with an uprising in favour of Ottokar, Vladislaus abdicated a few months later, on 6 December. Ottokar then took the Bohemian throne without imperial approval and compensated Vladislaus with the near-autonomous margravate of Moravia. By his repudiation of the throne, Vladislaus helped to bring an end to the destructive dynastic wars of the Přemyslids, which had lasted for over twenty-five years from the death of his father. He was the 25th and last duke of Bohemia
1342 Guy I Count of Blois Count of Blois and Lord of Avesnes 1307–1342.
1399 Demetrius I Starshy the second eldest son of Algirdas, Grand Duke of Lithuania, and his first wife Maria of Vitebsk. He was Duke of Bryansk from 1356 to 1379 and from 1388 to 1399
1452 Abraham Zacuto a Sephardi Jewish astronomer, astrologer, mathematician, rabbi and historian who served as Royal Astronomer in the 15th century to King John II of Portugal. The crater Zagut on the Moon is named after him
1481 Jorge de Lencastre Duke of Coimbra a Portuguese Prince, illegitimate son of King John II of Portugal and Ana de Mendonça, a maid of Joanna la Beltraneja. He became the second Duke of Coimbra in 1509. He was also master of the Order of Santiago and administrator of the Order of Aviz from 1492 to 1550
1503 Christian III of Denmark reigned as king of Denmark and Norway from 1534 until his death. He was the eldest son of King Frederick I and Anna of Brandenburg
1541 Ipatii Potii the Ukrainian Metropolitan of Kiev and Galychyna from 1599 to his death in 1613. He played an active role in the 1595 Union of Brest of which he was a firm supporter. He was also a writer, polemist and theologian
1566 Isabella Clara Eugenia sovereign of the Spanish Netherlands in the Low Countries and the north of modern France, together with her husband Albert. In some sources, she is referred to as Clara Isabella Eugenia. By birth, she was an infanta of Spain and Portugal
1575 James Hamilton 1st Earl of Abercorn a Scottish peer.
1591 Louise de Marillac the co-founder, with Saint Vincent de Paul, of the Daughters of Charity. She is venerated as a saint by the Roman Catholic Church
1604 Tokugawa Iemitsu the third shogun of the Tokugawa dynasty. He was the eldest son of Tokugawa Hidetada, and the grandson of Tokugawa Ieyasu. Iemitsu ruled from 1623 to 1651
1626 Giovanni Legrenzi an Italian composer of opera, vocal and instrumental music, and organist, of the Baroque era. He was one of the most prominent composers in Venice in the late 17th century, and extremely influential in the development of late Baroque idioms across northern Italy
1629 Archduchess Isabella Clara of Austria Not to be confused with Isabella Clara Eugenia, sovereign of the Netherlands.
1644 Heinrich Ignaz Franz Biber a Bohemian-Austrian composer and violinist. Born in the small Bohemian town of Wartenberg , Biber worked at Graz and Kroměříž before he illegally left his Kremsier employer and settled in Salzburg. He remained there for the rest of his life, publishing much of his music but apparently seldom, if ever, giving concert tours
1647 Johann Heinrich Acker a German writer. He sometimes wrote under the name of Melissander
1664 Magnus Stenbock a Swedish military officer at the time of the Great Northern War.
1666 Antonio Balestra an Italian painter of the Rococo period.
1666 Odoardo Farnese Hereditary Prince of Parma the son and heir of Duke Ranuccio II Farnese, Duke of Parma and Piacenza. He was the Hereditary Prince of Parma from his birth till his death. He was the father of the famously domineering Elisabeth Farnese
1686 John Balguy an English divine and philosopher.
1696 Maurice Greene (composer) an English composer and organist.
1712 Jonas Hanway born at Portsmouth, on the south coast of England.
1720 Konrad Ekhof a German actor, widely regarded as one of the foremost actors of the German-speaking realm in the 18th century.
1730 Edme-Louis Daubenton a French naturalist.
1737 Antoine-Augustin Parmentier remembered as a vocal promoter of the potato as a food source for humans in France and throughout Europe. His many other contributions to nutrition and health included establishing the first mandatory smallpox vaccination campaign and pioneering the extraction of sugar from sugar beets. Parmentier also founded a school of breadmaking, and studied methods of conserving food, including refrigeration
1756 Federico Carlos Gravina y Nápoli a Spanish Admiral during the American Revolution and Napoleonic Wars. He died of wounds sustained during the Battle of Trafalgar. Spanish explorer Jacinto Caamaño named the Gravina Island in Alaska in his honor
1759 Thomas Andrew Knight Coordinates: 52°22′01″N 2°49′01″W / 52.367°N 2.817°W / 52.367; -2.817.
1762 Christoph Wilhelm Hufeland a German physician. He is famous as the most eminent practical physician of his time in Germany and as the author of numerous works displaying extensive reading and a cultivated critical faculty
1762 George IV of the United Kingdom King of the United Kingdom of Great Britain and Ireland and of Hanover following the death of his father, George III, on 29 January 1820, until his own death ten years later. From 1811 until his accession, he served as Prince Regent during his father's final mental illness
1769 Ludwig Wilhelm Gilbert a German physicist and chemist, and professor of physics at the University of Leipzig. From 1799-1824 he published the "Annalen der Physik", of which Poggendorffs "Annalen der Physik und Chemie" was a continuation
1769 Johann Christian Martin Bartels a German mathematician. He was the tutor of Carl Friedrich Gauss in Brunswick and the educator of Lobachevsky at the University of Kazan
1773 Karl Faber a Prussian archivist and historian.
1774 Jean François Boissonade de Fontarabie a French classical scholar.
1774 Robert Southey an English poet of the Romantic school, one of the so-called "Lake Poets", and Poet Laureate for 30 years from 1813 to his death in 1843. Although his fame has been long eclipsed by that of his contemporaries and friends William Wordsworth and Samuel Taylor Coleridge, Southey's verse still enjoys some popularity
1779 George Grand Duke of Mecklenburg-Strelitz ruled the state of Mecklenburg-Strelitz from 1816 until his death.
1793 James Muspratt a British chemical manufacturer who was the first to make alkali by the Leblanc process on a large scale in the United Kingdom.
1795 Désiré Dalloz a French jurist, politician and publisher.
1799 Francis Abbott an Australian astronomer.
1800 Jean-Jacques Ampère a French philologist and man of letters.
1801 Julius Heinrich Petermann a German Orientalist.
1802 John Cadbury proprietor of a small chocolate business in Birmingham, England, that later became part of Cadbury plc, one of the world's largest chocolate producers. He developed an emulsification process to make solid chocolate - creating the modern chocolate bar
1804 Francesco Domenico Guerrazzi an Italian writer and politician involved in the Italian risorgimento.
1805 Johann Karl Rodbertus a German economist and socialist of the scientific or conservative school from Greifswald. He defended the labor theory of value as well as the view, as an inference from that, that interest or profit is theft. He believed that capitalist economies tend toward overproduction
1820 Avdotya Panaeva a Russian novelist, short story writer, memoirist and literary salon holder. She published much of her work under the pseudonym Stanitsky
1831 Helena Blavatsky a Russian philosopher, and occultist. In 1875, Blavatsky, Henry Steel Olcott, and William Quan Judge established a research and publishing institute called the Theosophical Society. Blavatsky defined Theosophy as "the archaic Wisdom-Religion, the esoteric doctrine once known in every ancient country having claims to civilization." One of the main purposes of the Theosophical Society was "to form a nucleus of the Universal Brotherhood of Humanity, without distinction of race, creed, sex, caste or color". Blavatsky saw herself as a missionary of this ancient knowledge
1837 Sven Berggren a Swedish botanist, explorer and university professor. He was a professor at Lund University 1883-1902, later at Uppsala University. He was elected a member of the Royal Swedish Academy of Sciences in 1880
1840 Charles MacGregor an Anglo-Indian explorer, geographer and officer of the British Indian Army. He was the Quartermaster General for the British Army in India, the head of the Intelligence Department for the British Indian Army and served under Frederick Roberts in the Second Anglo-Afghan War. The MacGregor Medal is awarded in his honour
1841 Franz Heinrich Schwechten one of the most famous German architects of his time, and has contributed to the development of the historicist architecture.
1841 Francesco di Paola Cassetta an Italian Cardinal of the Catholic Church who served as Prefect of the Sacred Congregation of the Council from 1914 until his death, and was elevated to the cardinalate in 1899.
1843 Colmar Freiherr von der Goltz a Prussian Field Marshal and military writer.