The siege of Orléans was Joan's greatest victory! The English had besieged the city for months. Joan, leading French troops, broke the siege in just nine days. She was wounded by an arrow but continued fighting. The victory was so decisive that the English never recovered. Within months, Charles VII was crowned king at Reims Cathedral (with Joan at his side). The Hundred Years' War ended in 1453 with French victory. Joan's trial was politically motivated. She was convicted of heresy and burned alive in Rouen's marketplace. Her ashes were scattered in the Seine River. Twenty-five years later, a retrial declared her innocent. She became a symbol of French unity and nationalism. Voltaire, Mark Twain, and George Bernard Shaw wrote about her. She is the patron saint of France.

The Mona Lisa is Leonardo's most famous painting! It was painted between 1503 and 1519. The painting was stolen from the Louvre in 1911 and recovered in 1913, which increased its fame. The identity of the sitter is uncertain but is believed to be Lisa Gherardini, the wife of a Florentine merchant. The painting's sfumato technique (soft, smoky transitions) and the mysterious smile have fascinated viewers for centuries. Leonardo's notebooks contain designs for a helicopter, a tank, a submarine, and a robot. He was also a musician and could play the lyre. He was left-handed and often wrote in mirror script (backwards, from right to left). Only about 15 of his paintings survive because he was a perfectionist and often left projects unfinished. He died in France, in the arms of King Francis I (according to legend).

Newton's Third Law is the "action-reaction" law! The story of the apple is likely apocryphal, but Newton did study falling objects. He developed calculus in 1665-1666 (his "annus mirabilis" or miracle year) but did not publish it until later, leading to a bitter dispute with Leibniz over priority. His book "Philosophiæ Naturalis Principia Mathematica" (1687) is considered the most important scientific work ever written. He also studied alchemy (unsuccessfully) and theology (he wrote more about religion than science). He served as President of the Royal Society (1703-1727) and as Master of the Royal Mint. He was knighted by Queen Anne in 1705. His face appears on British one-pound notes (old currency). He is buried in Westminster Abbey. Einstein kept a picture of Newton in his study.

Romeo and Juliet is one of Shakespeare's most famous plays! It has been adapted into countless films, ballets, operas, and musicals (including "West Side Story"). The play explores themes of love, fate, and family conflict. Shakespeare lived in Stratford-upon-Avon and London. He was a shareholder in the Globe Theatre (built 1599). His plays were performed for Queen Elizabeth I and King James I. The First Folio (1623), compiled by his friends, preserved 36 of his plays; without it, many would have been lost. He is buried in Holy Trinity Church in Stratford. His epitaph reads: "Good friend, for Jesus' sake forbear, to dig the dust enclosed here. Blest be the man that spares these stones, and cursed be he that moves my bones." No direct descendants survive (his granddaughter died childless).

Marie Curie discovered polonium and radium! She coined the term "radioactivity." She shared the 1903 Nobel Prize in Physics with her husband Pierre Curie and Henri Becquerel. After Pierre's death (1906, crushed by a horse-drawn carriage), she succeeded him as a professor at the Sorbonne (the first woman to teach there). She won the 1911 Nobel Prize in Chemistry for isolating pure radium. Her daughter Irène Joliot-Curie also won a Nobel Prize in Chemistry (1935). Marie Curie's remains were moved to the Panthéon in Paris in 1995 – she was the first woman honored there for her own achievements. Her notebooks are stored in lead-lined boxes and remain radioactive. The curie (unit of radioactivity) is named after her. She died at age 66. She was buried twice – first at the cemetery in Sceaux, then moved to the Panthéon.

E = mc² is Einstein's most famous equation! The speed of light (c) is approximately 299,792,458 meters per second. Because c² is a huge number, a small amount of mass can release enormous energy (nuclear bombs and nuclear power). Einstein was not involved in the Manhattan Project (he was denied security clearance). He later regretted his letter to Roosevelt, saying, "Had I known that the Germans would not succeed in producing an atomic bomb, I would never have lifted a finger." He was offered the presidency of Israel in 1952 (he declined). His brain was removed during his autopsy and preserved for scientific study (it was later found to have an unusual structure, but the significance is debated). He was named Time magazine's "Person of the Century" in 1999. His image is one of the most recognizable in the world.

Darwin's finches were key evidence! On the Galápagos Islands, Darwin noticed that finches on different islands had beaks suited to different foods: some had large, strong beaks for cracking seeds; others had slender beaks for catching insects. He later realized that they had evolved from a common ancestor. Darwin also studied tortoises (different shell shapes on different islands), mockingbirds, and fossils of extinct giant mammals in South America. His theory shocked Victorian society because it contradicted the biblical account of creation. The famous debate between Thomas Huxley ("Darwin's Bulldog") and Bishop Samuel Wilberforce took place in 1860. Darwin was buried in Westminster Abbey (near Isaac Newton). Modern evolutionary theory has been confirmed by genetics, the fossil record, and observation. Darwin's face appears on the British ten-pound note.

The Crimean War was Florence Nightingale's famous conflict! When she arrived, the military hospital at Scutari was filthy, overcrowded, and under-supplied. More soldiers died from infectious diseases (cholera, typhus) than from battle wounds. Nightingale insisted on cleanliness, fresh air, proper nutrition, and sanitation. Death rates dropped from 42% to 2% within six months. She was also a skilled statistician – she used polar area diagrams (similar to pie charts) to visualize mortality data. She was the first woman awarded the British Order of Merit (1907). She was often bedridden in later life (possibly from a chronic illness contracted during the Crimean War) but continued to work. International Nurses Day is celebrated on her birthday (May 12). The Florence Nightingale Pledge is sworn by new nurses. She was deeply religious and believed she was called by God.

Galileo discovered Jupiter's moons! He observed them in January 1610. This was a revolutionary discovery because it proved that celestial bodies could orbit something other than Earth, challenging the geocentric (Earth-centered) model. Galileo also observed the phases of Venus, which could only be explained by a heliocentric model. He wrote "Dialogue Concerning the Two Chief World Systems" (1632), comparing the Copernican and Ptolemaic models. The Church banned the book and put him on trial. He was forced to recant ("And yet it moves" – "E pur si muove" – is a famous quote he probably never said). He lived under house arrest for nine years, becoming blind before his death. He was a contemporary of Shakespeare (who died the same year). The Vatican formally acknowledged its error in 1992.

Marco Polo served the Mongol Empire! He arrived in China around 1275 and became a trusted emissary of Kublai Khan. He traveled extensively within China and possibly as far as Burma and India. The Polos (Marco, his father Niccolò, and uncle Maffeo) returned to Venice in 1295 after 24 years away. According to legend, they were unrecognizable and were not believed until they produced fabulous treasures. Marco was captured during a war between Venice and Genoa and dictated his book to a fellow prisoner, Rustichello da Pisa. Critics have questioned whether Polo actually reached China (noting omissions like the Great Wall, chopsticks, foot binding). Most scholars believe he did go to China but that his book exaggerates. "The Travels" became one of the most influential books in history. Columbus, Vasco da Gama, and John Cabot used it to plan their voyages. A species of sheep (Marco Polo sheep) is named after him.