| 3 April 1189 | Holy Roman Empire [diplomacy] | In the Peace of Strasbourg, Pope Clement III and the Holy Roman Emperor Frederick I Barbarossa resolve their differences over the appointment to the archbishopric of Trier in the Rhineland Palatinate. Both the papal and imperial candidates are dropped and a new election is held. |
| 3 April 1367 | Spain, England, France [wars] | Edward, Prince of Wales, the Black Prince, son of King Edward III of England, invades Castile on behalf of the usurped King Pedro I and defeats King Henry of Castile, capturing his French ally Bertrand du Guesclin at Nájera, Spain. Illness subsequently forces him to withdraw and new rebellions break out against King Pedro I. |
| 3 April 1789 | Sweden [legislation] | King Gustav III's act of unity and security in Sweden, granting him absolute powers, becomes law. |
| 3 April 1849 | Prussia, Germany [political events] | King Frederick Wilhelm IV of Prussia is unwilling to take the crown of a new united Germany from the people and wishes instead to receive it from the German princes. His vague reply is taken by the German National Assembly as a refusal. |
| 3 April 1860 | USA [postal services] | The Pony Express begins mail service between St Louis, Missouri and Sacramento, California. Riders change horses at 157 stations along the 2,897 km/1800 mi route and mail takes ten days. Within a few months it is made obsolete by the establishment of the transcontinental telegraph system. |
| 3 April 1913 | United Kingdom [suffrage] | Militant suffragist Emmeline Pankhurst is imprisoned in Britain for inciting persons to place explosives outside the house of the chancellor of the Exchequer, David Lloyd George. |
| 3 April 1924 | [births and deaths] | Marlon Brando, US actor, born in Omaha, Nebraska. |
| 3 April 1930 | Ethiopia [political events] | Ras Tafari, regent of Ethiopia, becomes emperor on the death of Empress Zauditu; he assumes the name Haile Selassie (‘Might of the Trinity’). |
| 3 April 1978 | UK [radio] | Regular radio broadcasts of the proceedings of the British Parliament begin. |
| 3 April 1988 | North Africa [diplomacy] | A peace agreement between Ethiopia and Somalia ends 11 years of border conflict. |
| 3 April 1991 | England, Switzerland [births and deaths] | Graham Greene, English novelist, dies in Vevey, Switzerland (86). |
| 3 April 2007 | France [railways] | France's TGV train sets a new world rail-speed record of 575 kph/357 mph on a new track between Strasbourg and Paris. |
