| April 15 | Swedish and Saxon army beat Earl Tilly |
| April 16 | Albrecht von Wallenstein appointed supreme commander |
| May 25 | Albrecht von Wallenstein recaptures Prague on Saksen |
| June 4 | Prince Frederik Henry conquerors Venlo |
| June 5 | Prince Frederik Henry conquerors Roermond |
| June 8 | Prince Frederik Henry conquerors Sittard |
| June 20 | Britain grants 2nd Lord Baltimore rights to Chesapeake Bay area |
| July 22 | Foundation laid in Madrid for Buen Retiro-palace for king Philip IV |
| August 22 | Prince Frederik Hendrik occupies Maastricht |
| August 28 | Henry Casimir I appointed viceroy of Drenthe |
| September 1 | Battle at Castelnaudary: Henri de Montmorency's rebellion army loses |
| September 3 | Battle at Nurnberg: Duke wallenstein beats Sweden |
| October 1 | Battle at Castelnaudary: Duke Henri de Montmorency's rebel army loses |
| October 5 | Henry Casimir I appointed viceroy of Groningen |
| November 6 | Battle at Lutzen: Swedish/Saxon army beats imperial armies |
| November 16 | Battle at Lutzen: Sweden beats imperial armies under Von Wallenstein |
