Cause of death: smallpox
Louis XV (15 February 1710 – 10 May 1774), known as Louis the Beloved (French: le Bien-Aimé), was King of France from 1 September 1715 until his death in 1774. He succeeded his great-grandfather Louis XIV at the age of five. Until he reached maturity (then defined as his 13th birthday) in 1723, the kingdom was ruled by his grand-uncle Philippe II, Duke of Orléans, as Regent of France. Cardinal Fleury was chief minister from 1726 until his death in 1743, at which time the king took sole control of the kingdom.
His reign of almost 59 years (from 1715 to 1774) was the second longest in the history of France, exceeded only by his predecessor, Louis XIV, who had ruled for 72 years (from 1643 to 1715). In 1748, Louis returned the Austrian Netherlands, won at the Battle of Fontenoy of 1745. He ceded New France in North America to Great Britain and Spain at the conclusion of the disastrous Seven Years' War in 1763. He incorporated the territories of the Duchy of Lorraine and the Corsican Republic into the Kingdom of France. Historians generally criticize his reign, citing how reports of his corruption embarrassed the monarchy, while his wars drained the treasury and produced little gain. However, a minority of scholars argue that he was popular during his lifetime, but that his reputation was later blackened by revolutionary propaganda. His grandson and successor Louis XVI inherited a large kingdom in need of financial and political reform which would ultimately lead to the French Revolution of 1789.
Source : Wikipedia