He didn't. The Roman republic collapsed basically because of stubborn political infighting. Titus Pullo is just a soldier mentioned by Julius Caesar in his War commentaries. That's all we know about him. If you want the fictionalized version of him, read a review of the movie Rome.

Rome - 2005 How Titus Pullo Brought Down the Republic 1-2 is rated/received certificates of:

Argentina:13

France:-12 (TV rating)

Germany:16

Netherlands:12

USA:TV-MA

Titus Pullo was a Roman centurion of the 11th Legion (Legio XI Claudia). He was mentioned very briefly by Julius Caesar in his Commentaries of the Gallic Wars. He became a main character in the HBO series Rome, probably because he was an actual historical figure. However, nothing is known about him except the couple of lines from Caesar.

The cast of Rome - 2011 includes: Lee Boardman as Timon Michael Nardone as Mascius Ray Stevenson as Titus Pullo

Rome - 2005 How Titus Pullo Brought Down the Republic 1-2 was released on:

USA: 4 September 2005

UK: 2 November 2005 (edited version) (part 1)

UK: 9 November 2005 (edited version) (part 2)

Germany: 22 January 2006

Hungary: 3 March 2006

Finland: 6 September 2006

Australia: 27 September 2006

Japan: 13 July 2007