"Louis XV" is a character based on Louis de Bourbon, duc d'Anjou, the great-grandson of Louis XIV, and the grandfather of Louis XVI, Louis XVIII, and Charles X.
Born on 15 February 1710 at the Bastille, his childhood was dominated by a series of tragic losses. His grandfather, Louis, le Grand Dauphin, died of smallpox on 14 April 1711. In February 1712, his parents - Louis, duc de Bourgogne, and Marie-Adélaïde de Savoia (great-aunt of La princesse de Lamballe) - died of smallpox within days of each other. His brother, Louis, duc de Bretagne, succumbed on 8 March after doctors treated his smallpox by bloodletting. Louis, also stricken with smallpox, would surely have died had his governess not nursed him around the clock and refused to let him be bled. With the death of Charles, duc de Berry, in a hunting accident on 5 May 1714, the Bourbons lost five male heirs in 14 years (Louis's other uncle having renounced his claim to the throne in 1700 to become Philip V of Spain.)
Louis XIV died of gangrene on 1 September 1715, having reigned for 72 years. He legitimated nine of his children, and named two sons to a Régence, structured in such a way that his nephew, Philippe II, duc d'Orléans, would head it in name only. But just before his death, the old king had a change of heart, ordering his ministers and courtiers to obey the duc as "he will govern the kingdom". On 2 September, the Parlements named Philippe régent, and gave him permission to form his own council. Louis, raised at the Palais des Tuileries, was declared his majority on his 13th birthday, ending the Régence. He was crowned Louis XV, King of France and Navarre on 25 October 1722.
Fearing that Philip V of Spain would claim the throne if the young king died without issue, Louis's handlers broke his engagement to Philip's daughter, Maria de Borbón, who was years away from child-bearing age; besides, she bored him. The 15 year old instead married the 22 year old Maria Leszczyska, daughter of the deposed King Stanisaw of Poland, on 4 September 1725, and moved the court to Versailles. The kindly but dull queen was overshadowed by the king's sophisticated lady friends, many of whom had supreme influence over the intelligent yet weak-willed monarch. His involvement in the War of the Austrian Succession was entirely due to the nagging of his mistress, the duchesse de Châteauroux. When Louis Ferdinand, dauphin de Viennois, the king's sole legitimate son, disobeyed orders and visited his deathly-ill father at Metz, the two became permanently estranged; Louis Ferdinand died in 1765.
The 1748 Treaty of Aachen ended the War and conflict between Austria and France. Louis and Empress Maria Theresa eventually contracted the marriage between his grandson, Louis-Auguste, and her daughter, Maria Antonia, to seal the alliance. But Louis hadn't learned from his involvement in the War, and plunged into the Seven Years' War with disastrous results: France lost Nouvelle-Orléans and the Nouvelle-France west of the Mississippi to Spain, and the Nouvelle-France east of the Mississippi to her arch-enemy, England.
Louis's inability to reform the monarchy, the failure of his foreign policies, and his general lack of morality cost him the love of his people. He died, ironically, of smallpox on 10 May 1774 at Versailles one of the most despised rulers in French history.