1st January » The legislative union of Kingdom of Great Britain and Kingdom of Ireland is completed to form the United Kingdom of Great Britain and Ireland.
1st January » The dwarf planet Ceres (dwarf planet) named Ceres is discovered by Giuseppe Piazzi.
31st January » John Marshall is appointed the Chief Justice of the United States.
4th February » John Marshall is sworn in as Chief Justice of the United States.
17th February » An U.S. Electoral College named electoral tie between Thomas Jefferson and Aaron Burr is resolved when Jefferson is elected President of the United States and Burr Vice President of the United States called Vice President by the United States House of Rep
27th February » Pursuant to the District of Columbia Organic Act of 1801, Washington, D.C. is placed under the jurisdiction of the Congress of the United States named U.S. Congress.
8th March » War of the Second Coalition: At the Battle of Abukir (1801) called Battle of Abukir, a British force under Sir Ralph Abercromby lands in Egypt with the aim of ending the French campaign in Egypt and Syria.
21st March » The Battle of Alexandria (1801) Battle of Alexandria is fought between United Kingdom British and France French forces near the ruins of Nicopolis in Egypt.
2nd April » Napoleonic Wars: Battle of Copenhagen The Kingdom of Great Britain named British capture the Danish fleet.
6th May » Captain Thomas Cochrane, 10th Earl of Dundonald Thomas Cochrane in the 14-gun HMS Speedy 1782 6 Action of 6 May 1801 captures the 32-gun Spanish frigate El Gamo Spanish frigate 'El Gamo'.
10th May » First Barbary War: The Barbary pirates of Tripoli declare war on the United States of America.
6th July » First Battle of Algeciras: Outnumbered French Navy ships defeat the Royal Navy in the fortified Spanish port of Algeciras.
11th July » French astronomer Jean-Louis Pons makes his first comet discovery. In the next 27 years he discovers another 36 comets, more than any other person in history.
12th July » French Revolutionary Wars: British Royal Navy ships inflict heavy damage against Spanish and French ships in the Second Battle of Algeciras.
1st August » First Barbary War: The American schooner USS Enterprise 1799 6 Action of 1 August 1801 captures the Tripolitan polacca 'Tripoli' in a list of single-ship actions single-ship action off the coast of modern-day Libya.
9th September » Alexander I of Russia confirms the privileges of Baltic governorates e.g Baltic provinces.