September 20th is the 263rd day of the year (264th in leap years) in the Gregorian calendar. There are 102 days remaining until the end of the year.
1260 – The second of two major Prussian uprisings by the Prussian tribe of Balts began against the Teutonic Knights.
1498 – A tsunami caused by the Nankai earthquake washed away the building housing the statue of the Great Buddha at Kōtoku-in in Kamakura, Japan.
1906 – The ocean liner RMS Mauretania, the largest and fastest ship in the world at the time, was launched.
1943 – World War II: Australian troops defeated Imperial Japanese forces at the Battle of Kaiapit in New Guinea.
2008 – An explosive-laden truck detonated in front of the Marriott hotel in Islamabad, Pakistan, killing 54 people and injuring 266 others.
Sophia Loren turns 84
George R.R. Martin turns 70
Asia Argento turns 43
Jon Bernthal turns 42