18th century
The 18th century was defined by the calendar of Earth as occurring from the year 1701 through the year 1800.

Events 
 The T'Lani and Kellerun declare war on each other. ()
 The people of Beta Portolan are overcome by a mass insanity, brought by the arrival of the flying parasites. ()
 Colonists from Peliar Zel first migrate to the planet's two moons. ()
 Hundreds of criminals from the planet Ux-Mal are imprisoned on a moon of Mab-Bu VI after their consciousnesses are permanently separated from their bodies. ()
 Chez Sandríne is opened in the city of Marseille on Earth. ()
 Napoléon Bonaparte rises to power in France, ushering in the Napoleonic era. This era continues into the early 19th century. (; )
 In France, according to Spock, this is the era of the swashbuckler. ()
 In America, a pair of glasses that are eventually given to James T. Kirk as a birthday present from Leonard McCoy are made in this century. ()

 William Herschel is born. ()

 Moët et Chandon is founded in the French town of Epernay. ()

 Tarquin is born at some point before this date. ()

 On May 18th of this year a lunar eclipse occurred on Earth at 10:07 at night. ()

 On April 1 of this year a solar eclipse occurs on Earth at 10:25 in the "forenoon". ()

 (circa)
 The planets Eminiar VII and Vendikar begin a bitter war. At some point the conflict becomes fought entirely in a computer simulation, and casualties are calculated based on projected results. ()

 The United States of America declares independence from Old Britain during the American Revolution. Under the military leadership of General George Washington and with the support of the French King, the rebellion is successful. (; )
 The Presidio, a future site of Starfleet Command and Starfleet Academy, is founded by Spain. ()

 The neutron star in a binary star system located in the Kavis Alpha sector explodes. ()

 Davy Crockett is born. ()

 The Constitution of the United States is adopted, and thereafter George Washington is elected President. ()

 Beginning of the period discussed in the book Memoirs of Frederick Perthes, or, Literary, religious, and political life in Germany, from 1789 to 1843. ()

 French military uniforms worn by the creations of Q on an unnamed planet are from this year. According to Data, the uniforms are be discontinued or changed in 1800. ()

Appendices

Background Information 
According to the  (3rd ed., pp. 60, 160, 183, 310, 319, & 323), the following events occur in this century:
 1727 – Isaac Newton dies.
 1756 – Wolfgang Amadeus Mozart is born.
 1758 – Horatio Nelson is born.
 1759 – Georg Friedrich Händel dies.
 1768 – Jean Baptiste Joseph Fourier, the inventor of the Fourier analysis, is born.
 1788 – Lord Byron is born.
 1791 – Wolfgang Amadeus Mozart dies.
 1795 – John Keats is born.

External links 
 
 

de:18. Jahrhundert
es:Siglo 18
fr:18ème siècle
it:XVIII secolo
nl:18e eeuw
pl:XVIII wiek