what year did the big bang bang theory start?
<answer> The Big Bang Theory's eleventh season will premiere Monday, September 25, 2017. <context> CBS has renewed the show for another two seasons, taking the show through to its twelfth season in 2018/19. The Big Bang Theory's eleventh season will premiere Monday, September 25, 2017. The Big Bang Theory stars Jim Parsons, Johnny Galecki, Kaley Cuoco, Simon Helberg, Kunal Nayyar, Mayim Bialik and Melissa Rauch.