- September 28, 0048 BC – Pompey the Great is assassinated on orders of King Ptolemy of Egypt after landing in Egypt.
- September 28, 0351 Battle of Mursa Major: the Roman Emperor Constantius II defeats the usurper Magnentius.
- September 28, 0365 “Roman usurper Procopius bribes two legions passing by Constantinople, and proclaims himself Roman emperor.”
- September 28, 0935 “Saint Wenceslas is murdered by his brother, Boleslav I of Bohemia.”
- September 28, 0995 “Members of Slavnk’s dynasty – Spytimr, Pobraslav, Poej and slav are murdered by Boleslaus’s son, Boleslaus II the Pious.”
- September 28, 0995 “Members of Slavník’s dynasty – Spytimír, Pobraslav, Porej and Cáslav are murdered by Boleslaus’s son, Boleslaus II the Pious.”
- September 28, 1106 “The Battle of Tinchebrai – Henry I of England defeats his brother, Robert Curthose.”
- September 28, 1322 “Louis IV, Holy Roman Emperor defeats Frederick I of Austria in the Battle of Mhldorf.”
- September 28, 1448 Christian I is crowned king of Denmark.
- September 28, 1542 “Juan Rodriguez Cabrillo discovers California, at San Diego Bay”
- September 28, 1542 “Navigator Juan Rodrguez Cabrillo of Portugal arrives as what is now San Diego, California, United States.”
- September 28, 1542 “Navigator Juan Rodríguez Cabrillo of Portugal arrives as what is now San Diego, California, United States.”
- September 28, 1779 “American Revolution: Samuel Huntington is elected President of the Continental Congress, succeeding John Jay.”
- September 28, 1781 “American forces backed by a French fleet begin the siege of Yorktown, Virginia, during the American Revolutionary War.”
- September 28, 1781 “Siege of Yorktown begins, last battle of the Revolutionary War”
- September 28, 1787 Congress sends Constitution to state legislatures for their approval
- September 28, 1787 The newly completed United States Constitution is voted on by the U.S. Congress to be sent to the state legislatures for approval.
- September 28, 1822 Sloop-of-war Peacock captures 5 pirate vessels
- September 28, 1823 Leo XII is elected pope.
- September 28, 1829 “Walker’s Appeal, racial antislavery pamphlet, published in Boston”
- September 28, 1844 Oscar I of Sweden-Norway is crowned king of Sweden.
- September 28, 1850 Flogging in US Navy & on merchant vessels abolished
- September 28, 1858 Donati’s comet becomes the first to be photographed
- September 28, 1867 Toronto becomes the capital of Ontario
- September 28, 1868 Battle of Alcolea causes Queen Isabella II of Spain to flee to France.
- September 28, 1868 “Battle of Alcolea, causes Queen Isabella 2 of Spain to flee to France”
- September 28, 1868 Opelousas Massacre at St Landry Parish Louisiana (200 blacks killed)
- September 28, 1871 Brazil passes law freeing future children of slavery.
- September 28, 1879 Sydney Australia innaugurates steam motor tram route
- September 28, 1889 “The first General Conference on Weights and Measures (CGPM) defines the length of a meter as the distance between two lines on a standard bar of an alloy of platinum with ten percent iridium, measured at the melting point of ice.”
- September 28, 1906 “US troops reoccupy Cuba, stay until 1909”
- September 28, 1912 “””Kiche Maru”” sinks off Japan, killing 1,000″
- September 28, 1914 German forces move into Antwerp Belgium (WW I)
- September 28, 1918 “Lt. Milton Fowler Gregg (Royal Canadian Regiment) wins the Victoria Cross at Cambrai, France”
- September 28, 1922 Mussolini marches on Rome
- September 28, 1924 “Two US Army planes end around-world flight, Seattle to Seattle, 57 stops”
- September 28, 1928 UK passed Dangerous Drugs Act (1925) – outlawing cannabis.
- September 28, 1928 UK passes the Dangerous Drugs Act (1925) outlawing cannabis.
- September 28, 1929 “The Hudson Bay Railway reaches its northern terminus at Churchill, Manitoba. This was originally operated by Canadian National on behalf of the Government. It became part of the CN system on September 5, 1951.”
- September 28, 1934 The Cunard-White Star Queen Mary launched at Clydebank