The X Factor is a British reality television music competition, and part of the global
X Factor franchise created by Simon Cowell. Premiering on 4 September 2004, it was produced by Fremantle's British entertainment company, Thames, and Cowell's production company Syco Entertainment for ITV, as well as simulcast on Virgin Media One in Ireland. The programme ran for around 445 episodes across fifteen series, each one primarily broadcast late in the year, until its final episode in December 2018. The majority of episodes were presented by Dermot O'Leary, with some exceptions: the first three series were hosted by Kate Thornton; while Caroline Flack and Olly Murs hosted the show for the twelfth series.