The siege of Orlans (12 October 1428 8 May 1429) was the watershed of the Hundred Years' War between France and England. It was the French royal army's first major military victory to follow the crushing defeat at the Battle of Agincourt in 1415, and also the first while Joan of Arc was with the army. The siege took place at the pinnacle of English power during the later stages of the war. The city held strategic and symbolic significance to both sides of the conflict. The consensus among contemporaries was that the English regent, John of Lancaster, would have succeeded in realizing his brother the English king Henry V's dream of conquering all of France if Orlans fell. For half a year the English and their French allies appeared to be winning, but the siege collapsed nine days after Joan's arrival.

Joan of Arc (French: Jeanne d'Arc pronounced [ʒan daʁk]; c. 1412 – 30 May 1431), who called herself "Joan the Maiden" ("Jehanne la Pucelle" in 15th-century French) and is now nicknamed "The Maid of Orléans" (French: La Pucelle d'Orléans), is considered a heroine of France for her role during the Lancastrian phase of the Hundred Years' War. She is also a saint in the Roman Catholic Church.

Joan was born to Jacques d'Arc and Isabelle Romée, a peasant family, at Domrémy in the Vosges of northeast France. In 1428, Joan, who was about 17 years old, traveled to Vaucouleurs and requested an armed escort to bring her to Charles VII of France. Joan later testified that she had received visions from the archangel Michael, Saint Margaret, and Saint Catherine instructing her to support Charles and recover France from English domination. Her request to see the king was rejected twice, but eventually the garrison commander Robert de Baudricourt relented and gave her an escort to meet Charles at Chinon. After their interview, Charles sent Joan to the siege of Orléans as part of a relief army. She arrived at the city on 29 April 1429, and quickly gained prominence for her role in lifting the siege nine days after she arrived in Orléans. During the following June, Joan played a key role in the Loire Campaign, which culminated in the decisive defeat of the English at the Battle of Patay. After the battle, the French army advanced on Reims and entered the city on 16 July. The next day, Charles was consecrated as the King of France in Reims Cathedral with Joan at his side. These victories boosted French morale and paved the way for the final French victory in the Hundred Years' War at Castillon in 1453.

After Charles' consecration, Joan and John II, Duke of Alençon's army besieged Paris. An assault on the city was launched on 8 September. It failed, and Joan was wounded by an arrow. The French forces withdrew and Charles disbanded the army. By October, Joan had recovered and participated in an attack on the territory of Perrinet Gressart, a mercenary who had been in the service of the English and Burgundian faction, a group of French nobles allied with the English. After some initial successes, the campaign ended in a failed attempt to take Gressart's stronghold at La-Charité-sur-Loire. By December, Joan was back at the French court, where she learned that she and her family had been ennobled by Charles.

In May 1430, Joan organized a company of volunteers to relieve Compiègne, which had been besieged by the Burgundians. She was captured by Burgundians troops on 23 May and afterwards exchanged to the English. She was put on trial by the pro-English bishop, Pierre Cauchon, on a charge of heresy. She was declared guilty and burned at the stake on 30 May 1431, dying at about 19 years of age.

In 1456, an inquisitorial court authorized by Pope Callixtus III investigated the original trial, which was found to have been by deceit, fraud and incorrect procedure. The verdict of Joan's original trial was nullified and the stain on Joan's name declared to be erased. Joan has been popularly revered as a martyr since her death, and after the French Revolution she became a national symbol of France. She was beatified in 1909, canonized in 1920, and declared a secondary patron saint of France in 1922. Joan of Arc has remained a popular figure in literature, painting, sculpture, and other cultural works since the time of her death, and many famous writers, playwrights, filmmakers, artists, and composers have created, and continue to create cultural depictions of her.