1800s

Technology

 * Invention of the in.
 * is discovered by.
 * is gradually adopted by various of the world.
 * is isolated from for the first time in.
 * develops a method to preserve food by means of.

Astronomy

 * The first known are discovered in this decade:
 * . Ceres is reclassified as a  in.

War, peace and politics

 * The (–) is fought between the  and the  of.
 * The and the  merge into the  in 1801.
 * In, the US acquired the from.
 * The (-) is fought between the  on one side and minor chieftains of the Maratha Confederacy, and  on the other resulting in a crushing defeat of the rebel chieftains and the breakup of the Maratha confederacy.
 * gains from France on, becoming the first.
 * The (–) is fought in present day  and.
 * The (−) marks the first time in 300 years  perceives itself an independent state.
 * Beginning of the (–).
 * Beginning of the between  and the.

Other

 * The (–)

World leaders

 * Emperor
 * Emperor
 * Tsar (Russia)
 * King
 * King ,
 * President (United States)
 * of
 * of
 * 1)  1759-1806
 * 2)  1806-1837
 * ( of the )
 * Maharaja  1801-1839
 * 1)  1759-1806
 * 2)  1806-1837
 * ( of the )
 * Maharaja  1801-1839
 * Maharaja  1801-1839