Factual error: Toby joins the War Office, handles statistics for the RAF (an Air Ministry job) and then is suddenly said to be working for the Admiralty, but still in the same office in which he has been working since the beginning of the war. These were three completely separate ministries with separate buildings. Civil servants joined one or the other.
The Halcyon (2017)
1 factual error in show generally
Starring: Olivia Williams, Steven Mackintosh, Jamie Blackley, Hermione Corfield
Genres: Drama
Episode #1.3 - S1-E3
Factual error: Billy is called up into a specific unit of the Royal Artillery. This didn't happen. He would first have been sent to a Royal Artillery training depot and only after training would he have been assigned to a unit.