Major Events
- Jan 25 Tsar Peter the Great makes the Moscow patriarchate and Russian Orthodox Church subordinate to the state
- Mar 9 British Chancellor Exchequer John Aislabie confined in London Tower
- Mar 24 Johann Sebastian Bach dedicates his Brandenburg Concertos to Christian Ludwig, Margrave of Brandenburg-Schwedt
- Mar 27 France & Spain sign Treaty of Madrid
- Apr 3 Robert Walpole becomes Britain's 1st Lord of the Treasury - effective Prime Minister, although that term was never officially used (indeed, it was considered an insult) until much later
- Apr 22 HMS Seahorse infected with smallpox arrives in Boston harbor, causing the first outbreak in two decades. - half of the population catch it, causing 850 deaths [1]
- May 8 Michelangiolo dei Conti succeeds Pope Clement XI, as Innocent XIII
- May 25 John Copson becomes America's 1st insurance agent
- May 29 South Carolina formally incorporated as a royal colony
- Jun 13 England signs Treaty of Madrid
- More 1721 Events
1721 in Music
- Mar 24 Johann Sebastian Bach dedicates his Brandenburg Concertos to Christian Ludwig, Margrave of Brandenburg-Schwedt