Factual error: The scene with Queen Victoria in Florence happens too early since it is supposed to happen in the spring of 1888 but Abdul Karim was not yet her official "Munshi", being appointed to that title in August of the same year.
Factual error: Performing for Queen Victoria is the famous opera composer Giacomo Puccini. This happens during her sojourn in Florence in 1888. Puccini was born in 1858, so he was barely thirty years of age, but the actor portraying him, Simon Callow, is in his late 60s (and it shows). Moreover, he is presenting his latest creation "Manon Lescaut"; in 1888 he hadn't even started working on it.
Continuity mistake: When the soup is about to be served, you see the horns blowing to introduce Victoria, and you can see all of the footmen lined up already with trays of soup, but in the next shot, it shows that they are just starting to march in to line up with their trays of soup. (00:10:45)