The series Downton Abbey is set to begin in April 1912, in the immediate aftermath of the Titanic disaster, but the most likely in‑story date for the opening episode is April 16, 1912. In real life, the TV show itself first premiered in the UK on ITV on 26 September 2010.

Quick Scoop

  • In‑universe, the story kicks off in April 1912 , when the Crawley family learns news of the Titanic sinking and the death of Downton’s heir.
  • Fan and wiki analyses narrow this to around 16 April 1912 , which matches when the news would plausibly reach England via telegram and newspapers.
  • On screen, the first episode simply labels the time as “April 1912” rather than giving a specific day.
  • As a TV show, Downton Abbey started airing on 26 September 2010 on ITV in the UK, later reaching the US on PBS in January 2011.

So, if you’re asking “when did Downton Abbey start?” in terms of the story: April 1912; if you mean the show on TV: 26 September 2010.

TL;DR: Story start = April 1912 (likely the 16th); TV premiere = 26 September 2010.

Information gathered from public forums or data available on the internet and portrayed here.