Episode #1.1 - S1-E1
Factual error: Thomas' record says he received the King's Medal for Gallantry in the First World War. There was no such medal. It would have been the Military Medal.
Episode #1.1 - S1-E1
Factual error: Ada is watching a movie and when asked "tell me the man's name" says "Rudolph Valentino." Valentino was largely unknown in 1919, only appearing in bit parts. She is also eating popcorn. This was not done in movie theaters until the 1930, unless you brought your own. Only street vendors sold popcorn.
Suggested correction: This is from episodes #1.2 and two separate mistakes. But being "largely unknown" doesn't mean she couldn't know his name. And who's to say she didn't buy the popcorn from a street vendor? You don't see others eating popcorn, so there's no suggestion she bought it there.
He used the name Rudolph Valentino for the first time in 1921.
That's not true since he was credited as Rudolph as early as 1917.
Episode #1.3 - S1-E3
Factual error: When attempting to arrest Grace one of the supposed IRA men proclaims that he is taking her into custody "on behalf of the Irish Free State." The term "Irish Free State" was not a term used by republicans or generally until the Anglo-Irish Agreement which led to the end of the War of Irish Independence and the establishment of the Irish Free State in 1922. Anyone representing the IRA would have, when speaking English, referred to the Irish Republic at that time.
Episode #1.3 - S1-E3
Factual error: One of the men who approaches Tommy claiming to be representatives of the IRA sings the song "The Boys of the Old Brigade." The song is told from the perspective of an elderly veteran of the Irish war of independence which had only began in January of 1919 which had happened only 3 years before. The song was written by Paddy McGuigan of the band Barleycorn in the 1970's.
Episode #1.4 - S1-E4
Factual error: When Freddy and Ada return to Birmingham from London they are seen on a boat called Kennet. This is a wide boat (i.e. almost twice the width of a 7 ft narrowboat) which could not have made its way from London to Birmingham in 1919/20 as all of the locks were narrow locks (7 ft) at that time.
Episode #1.4 - S1-E4
Factual error: In 1919 Chapman receives £200 from the Russian Embassy, but diplomatic relations were not established until 1924.
