On this day in history 20 December
1991: Paul Keating becomes Prime Minister of Australia after rolling Bob Hawke for leadership of the Labor party.
1992: Slobodan Milošević re-elected president of Serbia.
1996: Horror film classic "Scream", starring Neve Campbell and Courteney Cox, is released.
2002: "Gangs of New York", starring Leonardo DiCaprio, Daniel Day-Lewis, and Cameron Diaz, is released.
2005: "The Breakthrough" 7th studio album by Mary J. Blige is released.
2007: Her Majesty Queen Elizabeth II becomes the oldest ever monarch of the United Kingdom, surpassing Queen.
2007: The painting Portrait of Suzanne Bloch (1904), by the Spanish artist Pablo Picasso.
2009: US President Barack Obama receives his vaccine jab against swine flu.
2017: Lady Gaga signs Las Vegas residency deal for $75m at MGM Park Theatre.
2018: US Defence Secretary Jim Mattis announces his resignation after disagreements with President Donald Trump.