Died on May 21

822 Al-Hakam I Umayyad Emir of Cordoba from 796 until 822 in the Al-Andalus.
987 Louis V of France the King of Western Francia from 986 until his premature death. He died childless and was the last monarch in the Carolingian line
1086 Wang Anshi a Chinese economist, statesman, chancellor and poet of the Song Dynasty who attempted controversial, major socioeconomic reforms. These reforms constituted the core concepts and motives of the Reformists, while their nemesis, Chancellor Sima Guang, led the Conservative faction against them
1237 Olaf the Black a mid 13th century sea-king who ruled the Isle of Man and parts of the Hebrides. Óláfr was the son of Guðrøðr Óláfsson, King of the Isles, King of Dublin, and his wife Finnguala, granddaughter of Muirchertach Mac Lochlainn, High King of Ireland, King of Cenél nEógain. Óláfr was a younger son of his father; his elder brother Rögnvaldr more than likely had a different mother. According to the Chronicle of Mann, Guðrøðr appointed Óláfr as heir since he had been born "in lawful wedlock". Whether or not this is the case, on Guðrøðr's death in 1187 the Manxmen instead appointed Rögnvaldr as king, as he was a capable adult and Óláfr was a mere child. Rögnvaldr ruled the Crovan dynasty's island-kingdom for almost 40 years, during which time the half-brothers vied for the kingship
1254 Conrad IV of Germany Duke of Swabia , King of Jerusalem , King of Germany , and of King of Sicily.
1297 Judith of Habsburg the youngest daughter of Rudolph I of Germany and his wife Gertrude of Hohenburg. Judith was a member of the Habsburg family
1381 Frederick III Landgrave of Thuringia the son of Frederick II, Margrave of Meissen and Mathilde of Bavaria.
1425 Parisina Malatesta the daughter of Andrea Malatesta, lord of Cesena, and his second wife, Lucrezia Ordelaffi. She had affair with her bastard stepson Ugo d'Este, and both were beheaded by her husband Marquis Niccolò III d'Este of Ferrara
1471 Henry VI of England King of England from 1422 to 1461 and again from 1470 to 1471, and disputed King of France from 1422 to 1453. Until 1437, his realm was governed by regents. Contemporaneous accounts described him as peaceful and pious, not suited for the dynastic wars, such as the Wars of the Roses, which commenced during his reign. His periods of insanity and his inherent benevolence eventually required his wife, Margaret of Anjou, to assume control of his kingdom, which contributed to his own downfall, the collapse of the House of Lancaster, and the rise of the House of York
1481 Christian I of Denmark a Danish monarch of the Oldenburg dynasty, King of Denmark , Norway and Sweden , under the Kalmar Union. In Sweden his short tenure as monarch was preceded by regents, Jöns Bengtsson Oxenstierna and Erik Axelsson Tott and succeeded by regent Kettil Karlsson Vasa. Also Duke of Schleswig and Holstein 1460–81
1512 Pandolfo Petrucci a ruler of the Italian city of Siena during the Renaissance.
1524 Thomas Howard 2nd Duke of Norfolk the only son of John Howard, 1st Duke of Norfolk, by his first wife, Katherine Moleyns. The Duke was the grandfather of both Queen Anne Boleyn and Queen Catherine Howard and the great grandfather of Queen Elizabeth He served four monarchs as a soldier and statesman
1541 Johann Faber a Catholic theologian known for his writings opposing the Protestant Reformation and the growing Anabaptist movement.
1542 Hernando de Soto a Spanish explorer and conquistador who led the first European expedition deep into the territory of the modern-day United States , and the first documented European to have crossed the Mississippi River.
1563 Martynas Mažvydas the author and the editor of the first printed book in the Lithuanian language.
1607 John Rainolds an English academic and churchman, of Puritan views. He is remembered for his role in the Authorized Version of the Bible, a project of which he was initiator
1619 Hieronymus Fabricius a pioneering anatomist and surgeon known in medical science as "The Father of Embryology.".
1639 Tommaso Campanella an Italian philosopher, theologian, astrologer, and poet.
1647 Pieter Corneliszoon Hooft a Dutch historian, poet and playwright from the period known as the Dutch Golden Age.
1650 James Graham 1st Marquess of Montrose a Scottish nobleman, poet and soldier, who initially joined the Covenanters in the Wars of the Three Kingdoms, but subsequently supported King Charles I as the English Civil War developed. From 1644 to 1646, and again in 1650, he fought a civil war in Scotland on behalf of the King and is generally referred to in Scotland as simply "the Great Montrose"
1654 Elizabeth Poole an English settler in Plymouth Colony who founded the town of Taunton, Massachusetts. She was the first woman known to have founded a town in the Americas. Poole was a well-born woman from Shute in East Devon, near Axminster. She was the daughter of Sir William Pole, who was knighted by James I in 1601, and Mary Peryam, the daughter of Sir William Peryam, Lord Chief Baron of the Exchequer. Until 2009, her family's descendants, the Pole-Carews, lived in the Devonshire house she was born in, Shute Barton a National Trust property which is open to the public on four weekends during the year
1670 Niccolò Zucchi an Italian Jesuit, astronomer, and physicist.
1690 John Eliot (missionary) a Puritan missionary to the American Indians whom some called “the apostle to the Indians.”.
1715 Pierre Magnol a French botanist. He was born in the city of Montpellier, where he lived and worked for the biggest part of his life. He eventually became Professor of Botany and Director of the Royal Botanic Garden of Montpellier and even held a seat in the Académie Royale des Sciences de Paris for a short while. Magnol is of lasting importance because he was one of the innovators of the current botanical scheme of classification. He was the first to publish the concept of plant families as we know them, a natural classification, in which groups of plants with associated common features were described
1724 Antonio Salvi an Italian physician, court poet and librettist. He was in the service of the ducal court in Florence and the favourite librettist of Prince Ferdinando de' Medici. Salvi was one of the developers of the opera seria
1724 Robert Harley 1st Earl of Oxford and Earl Mortimer a British politician and statesman of the late Stuart and early Georgian periods. He began his career as a Whig, before defecting to a new Tory Ministry. Between 1711 and 1714 he served as Lord High Treasurer, effectively Queen Anne's chief minister. He has been called a Prime Minister, though it is generally accepted that the position was first held by Sir Robert Walpole in 1721
1732 Sebastiano Mocenigo doge of Venice from 1722 to 1732.
1740 Antonio Balestra an Italian painter of the Rococo period.
1742 Lars Roberg a Swedish physician.
1769 Gottfried Heinsius a German mathematician, geographer and astronomer.
1771 Maria Zofia Czartoryska a Polish szlachcianka.
1771 Christopher Smart an English poet. He was a major contributor to two popular magazines and a friend to influential cultural icons like Samuel Johnson and Henry Fielding. Smart, a high church Anglican, was widely known throughout London
1786 Carl Wilhelm Scheele a Swedish Pomeranian pharmaceutical chemist. Isaac Asimov called him "hard-luck Scheele" because he made a number of chemical discoveries before others who are generally given the credit. For example, Scheele discovered oxygen , and identified molybdenum, tungsten, barium, hydrogen, and chlorine before Humphry Davy, among others. Scheele discovered organic acids tartaric, oxalic, uric, lactic, and citric, as well as hydrofluoric, hydrocyanic, and arsenic acids. He preferred speaking German to Swedish his whole life, and German was commonly spoken among Swedish pharmacists
1790 Thomas Warton an English literary historian, critic, and poet. From 1785 to 1790 he was the Poet Laureate of England. He is sometimes called Thomas Warton the younger to distinguish him from his father Thomas Warton the elder. His most famous poem remains The Pleasures of Melancholy, a representative work of the Graveyard poets
1796 Alexei Ivanovich Belsky a Russian painter. He was part of the "Belsky Dynasty" of painters of the Eighteenth Century and a teacher at the Imperial Academy of Arts. He specialized in landscapes, allegories and historical subjects
1800 Carl August Ehrensvärd a Swedish naval officer, painter, author, and neo-classical architect.
1806 Princess Maria Antonia of Naples and Sicily the youngest daughter of Ferdinand, King of Naples and Sicily, and Maria Carolina of Austria. As the wife of the future Ferdinand VII of Spain, then heir apparent to the Spanish throne, she held the title of Princess of Asturias
1809 Jean-Louis-Brigitte Espagne a French cavalry commander of the French Revolutionary Wars, who rose to the top military rank of General of Division and took part to the Napoleonic Wars.
1810 Chevalier d'Eon a French diplomat, spy and soldier who fought in the Seven Years War. D'Éon had androgynous physical characteristics and natural abilities as a mimic, good features for a spy. D'Éon appeared publicly as a man and pursued masculine occupations for 49 years, although during that time d'Éon successfully infiltrated the court of Empress Elizabeth of Russia by presenting as a woman. For 33 years, from 1777, d'Éon dressed as a woman, claiming to be assigned female at birth. Doctors who examined the body after d'Éon's death discovered that d'Éon would have actually been assigned male at birth
1812 Joseph Wölfl an Austrian pianist and composer.
1814 Ignacio Jordán Claudio de Asso y del Río a Spanish diplomat, naturalist, lawyer and historian. He sometimes used the pseudonym of Melchor de Azagra
1817 Johan Christopher Toll born at Mölleröd in Scania. Toll came of an ancient family, of Dutch origin, which can be traced back to the 13th century, but migrated to the Baltic provinces in the 16th century
1825 Stepan Davydov a Russian composer and singer.
1829 Peter I Grand Duke of Oldenburg the Regent of the Duchy of Oldenburg for his incapacitated cousin Peter Frederick William from 1785 to 1823, and then served himself as Duke from 1823-1829.
1839 José María Heredia y Heredia a Cuban poet, born at Santiago de Cuba.
1839 Johann Christoph Friedrich GutsMuths especially known for his role in the development of physical education. He is thought of as the "grandfather of gymnastics" – the "father" being Turnvater Jahn. GutsMuths introduced systematic physical exercise into the school curriculum, and he developed the basic principles of artistic gymnastics
1841 Julian Ursyn Niemcewicz a Polish poet, playwright and statesman. He was a leading advocate for the Constitution of 3 May 1791
1844 Giuseppe Baini an Italian priest, music critic, and composer of church music.
1848 Pierre Wantzel a French mathematician who proved that several ancient geometric problems were impossible to solve using only compass and straightedge.
1850 Christoph Friedrich von Ammon a German theological writer and preacher. He was born at Bayreuth, Bavaria and died at Dresden