Historic Publication
Feb 22 Galileo's "Dialogue Concerning the Two Chief World Systems" is published
Galileo Galilei
- Mar 29 Treaty of Saint-Germain is signed, returns Quebec to French control after the English seized it in 1629
- Apr 15 Battle of Rain; Swedes under Gustavus Adolphus defeat Count Tilly of the Holy Roman Empire during the Thirty Years' War.
- Apr 16 Albrecht von Wallenstein appointed supreme military commander of the Holy Roman Empire
- May 25 Albrecht von Wallenstein recaptures Prague on Saksen
Victory in Battle
Jun 4 Prince Frederick Henry conquers Venlo
Frederick Henry
- Jun 5 Prince Frederick Henry conquers Roermond
- Jun 8 Frederick Henry, Prince of Orange, conquers Sittard
- Jun 20 Britain grants 2nd Lord Baltimore rights to Chesapeake Bay area
- Jul 22 Foundation laid in Madrid for Buen Retiro Palace for King Philip IV
- Jul 23 Three hundred colonists bound for New France depart from Dieppe, France.
- Aug 22 Prince Frederick Henry occupies Maastricht
- Aug 28 Henry Casimir I appointed viceroy of Drenthe
- Sep 1 Battle at Castelnaudary: Henri de Montmorency's rebellion army loses
- Sep 3 Battle of Nuremberg: Duke Wallenstein beats Sweden
- Oct 1 Battle at Castelnaudary: Duke Henri de Montmorency's rebel army loses
- Oct 5 Henry Casimir I appointed viceroy of Groningen
- Nov 6 Battle at Lutzen: Swedish/Saxon army beats imperial armies
- Nov 16 Battle of Lützen: Sweden beats imperial armies under Albrect von Wallenstein