The 18th century lasted from January 1, 1701 to December 31, 1800. During the 18th century, elements of Enlightenment thinking culminated in the American, French, and Haitian revolutions. During the century, slave trading and human trafficking expanded on a global scale. Revolutions began to challenge the legitimacy of monarchical and aristocratic power structures, including the structures and beliefs that supported the slave trade.

The period is also known as the "century of lights" or the "century of reason". In continental Europe, philosophers dreamed of a brighter age. For some, this dream turned into a reality with the French Revolution of 1789, though this was later compromised by the excesses of the Reign of Terror. At first, many monarchies of Europe embraced Enlightenment ideals, but in the wake of the French Revolution they feared loss of power and formed broad coalitions for counter-revolution.

18th century music includes works characteristic of the Late Baroque period (including Johann Sebastian Bach and George Frideric Handel) and the classical period (including Joseph Haydn and Wolfgang Amadeus Mozart).

The Ottoman Empire experienced an unprecedented period of peace and economic expansion, taking part in no European wars from 1740 to 1768. As a consequence, the empire was not exposed to Europe's military improvements of the Seven Years' War (1756–1763). The Ottoman empire military may have fallen behind and suffered defeats against Russia in the second half of the century.

The 18th century also marked the end of the Polish–Lithuanian Commonwealth as an independent state. The formerly powerful and vast kingdom, which had once conquered Moscow and defeated great Ottoman armies, collapsed under numerous invasions. Its semi-democratic government system was not robust enough to rival the neighboring monarchies of the Kingdom of Prussia, the Russian Empire and the Austrian Empire which divided the Commonwealth territories between themselves, changing the landscape of Central Europe and politics for the next hundred years.

European colonization of the Americas and other parts of the world intensified and associated mass migrations of people grew in size as the Age of Sail continued.

Great Britain became a major power worldwide with the French and Indian War in the 1760s and the conquest of large parts of India, especially Bengal. However, Britain lost many of its North American colonies after the American Revolution and Indian wars. In North America, the defeat of the British resulted in the formation of an independent United States.

In Central Asia, Nader Shah led successful military campaigns and major invasions, which led to the founding of the Durrani Empire.

In the Indian subcontinent, the death of the Islamic Mughal Emperor Aurangzeb marked the end of medieval India. It marked the beginning of modern India and the era of extensive European intervention in the subcontinent. The victory of the British East India Company over the Nawab of Bengal and their French allies[1] in the Battle of Plassey caused the deindustrialization of Bengal and the beginning of the British Industrial Revolution which radically changed human society and the environment. The British invasion expanded to cover much of South Asia.

French-Italian emperor Napoleon Bonaparte, formed one of the Franco-Indian alliances with the major economic power Kingdom of Mysore,[2] governed by Tipu Sultan and his father Hyder Ali, who pioneered the use of Rocket artillery and the world's first iron-cased rockets, the Mysorean rockets, through the compilation of the Fathul Mujahidin.[3][4] The Anglo-Mysore Wars were fought and the Treaty of Mangalore was initiated in 1784.

Western historians have occasionally defined the 18th century otherwise for the purposes of their work. For example, the "short" 18th century may be defined as 1715–1789, denoting the period of time between the death of Louis XIV of France and the start of the French Revolution, with an emphasis on directly interconnected events.[5][6] To historians who expand the century to include larger historical movements, the "long" 18th century[7] may run from the Glorious Revolution of 1688 to the Battle of Waterloo in 1815[8] or even later.[9]