Factual error: During any British election, the Queen avoids making public appearances in order to avoid influencing the election turnout. She usually stays at Windsor castle and would not have hosted such events as the garden party.
Factual error: When Henry is showing Daphne the portraits of her ancestors, he indicates that Field Marshall Dashwood lost an arm at the Battle of the Nile.....interesting, because the Nile was a naval battle, and the field Marshall was in the army.
Factual error: In the scene at the fashion show, many of the photographers are using Speed Graphic press cameras. These are classic cameras, and no longer used today because of their large size.