Kepler

 The great astronomer Johannes Kepler was born on 27 December 1571. 

Queen Zenobia

 Queen Zenobia was born on 23 December 245. Zenobia was the queen of Palmyra in what is now Syria from about 268 AD to 272 AD. She fought the Romans and conquered Egypt. However, Zenobia was eventually defeated and captured. www.localhistories.org/womenrulers.html

Radium

 On 21 December 1898 Pierre Curie and his wife Marie discovered radium. Well done Pierre and Marie. www.localhistories.org/pierre.html

Australia

 I wrote a brief history of Australia www.localhistories.org/australia.html

Joseph Stalin

 The tyrant Joseph Stalin was born on 18 December 1878

Catherine of Aragon

 Catherine of Aragon, the first wife of Henry VIII was born on 16 December 1485 

Tycho Brahe

 The great Danish astronomer Tycho Brahe was born on 14 December 1546. Sadly he died shortly before the telescope was invented. It's a pity because he would have loved to look through one.