17 September in history
9 events that happened on 17 September, from 1111 to 1978.
1111 CE 915 years ago
The child Alfonso VII is crowned king of Galicia
The Galician high nobility, led by Pedro Fróilaz de Traba, crowned the child Alfonso VII king of Galicia at Santiago de Compostela, and Bishop Diego Gelmírez anointed him. The coronation was meant to preserve his rights in Galicia.
✦ Anniversary of the day
1176 CE 850 years ago
Seljuk forces ambush Manuel I Komnenos at Myriokephalon
The Seljuk sultan Kilij Arslan II ambushed the army of the Byzantine emperor Manuel I Komnenos in a narrow pass as it marched on Konya. Manuel escaped and agreed a truce, but the defeat ended Byzantine hopes of recovering central Anatolia.
1382 CE 644 years ago
Louis the Great's daughter Mary is crowned ruler of Hungary
After Louis I of Hungary died without a male heir, his daughter Mary was crowned with the title of "King" of Hungary. She reigned until 1385 and again from 1386, while her sister Jadwiga succeeded Louis in Poland.
1462 CE 564 years ago
Piotr Dunin's Polish army defeats the Teutonic Knights at Świecino
In the Thirteen Years' War, Polish forces under Piotr Dunin, some 2,000 mercenaries and Poles, decisively defeated the 2,700-man army of the Teutonic Knights under Fritz Raweneck and Kaspar Nostitz. Duke Eric II of Pomerania's auxiliaries stayed out of the battle.
1787 CE 239 years ago
Delegates sign the US Constitution in Philadelphia
Thirty-nine delegates signed the Constitution, creating a federal government with separated powers and checks and balances. The Bill of Rights was added by amendment in 1791.
1862 CE 164 years ago
The Battle of Antietam, America's bloodiest single day
Union and Confederate armies suffered about 23,000 casualties along Antietam Creek in Maryland. Lee's retreat gave Lincoln the victory he needed to announce the Emancipation Proclamation.
1978 CE 48 years ago
Egypt and Israel sign the Camp David Accords
After 13 days of talks hosted by Jimmy Carter, Anwar Sadat and Menachem Begin signed two frameworks for peace. They led to the Egypt-Israel peace treaty of March 1979.
Born on 17 September 4
Died on 17 September 7
Dates as the sources give them: in the Julian calendar before 1582, and in some countries for longer (Britain until 1752, Russia until 1918). Only people whose day of birth or death the records agree on are listed.