1798

1798 (MDCCXCVIII) was a common year starting on Monday in the Gregorian calendar and a common year starting on Friday in the Julian calendar. 

 Events 
 January 22 – Coup d'état in the Netherlands (Batavian Republic). Unitarian Democrat Pieter Vreede makes an end to the power of the parliament (with a conservative-moderate majority).
 7 March – French forces invade the Papal States and establish the Roman Republic
 April 7 – The Mississippi Territory is organized from territory from Georgia and South Carolina and is later twice made larger to include disputed land claimed by both the U.S. and Spain
 April 26 – France leaves Geneva
 May 24 – Irish nationalists start bloody rebellion against British occupation.
 June 12 – French take Malta
 June 12 – Coup d'état in the Netherlands (Batavian Republic). Moderates depose Pieter Vreede.
 July 1 – Napoleon's troops land in Egypt
 July 14 – The Alien and Sedition Acts become United States law making it a federal crime to write, publish, or utter false statements about the United States government
 July 21 – Napoleon defeats Mameluke forces near the Pyramids
 July 24 – Napoleon occupies Cairo
 July 30 – Selim III defeats Napoleon in Egypt
 July 31 – Second elections in the Netherlands (Batavian Republic). No general elections this time.
 August 1 – Horatio Nelson defeats the French navy under Admiral Brueys at the Battle of the Nile. Nelson himself is injured on the head.
 August 22 – French troops land at Killala in County Mayo to assist Irish rebellion.
 September 18 – Lyrical Ballads published anonymously by Samuel Taylor Coleridge and William Wordsworth

Franz Xaver, Baron Von Zach, Scientific Editor, Astronomer, begins editing journals about navigation and the geographic positions of cities.
XYZ Affair in the U.S., followed by naval battles, but no war is declared.
 First mechanical music boxes
 Alessandro Volta and La Place discover electricity
 The Afghans Army occupied Lahore in Punjab
 Aarau is the temporary capital of the Helvetic Republic
 Alois Senefelder invents lithography
 Eli Whitney contracts with the US Federal Government for 10,000 rifles, which he produces with interchangeable parts
 Charles Brockden Brown publishes the first American Novel Wieland or The Transformation an American Tale

 Ongoing events 
 French Revolution (1789-1799) Revolutionary Wars (1792-1802)-Second Coalition/Egyptian Campaign
 May-October – Irish Rebellion of 1798