The Spanish Royal Palace of El Escorial, residence of King Philip II, is misspelled in the title card as El Escurial.
Queen Elizabeth uses a small telescope to check on the progress of her fleet against the Spanish Armada (1588). The telescope was invented in 1608, five years after her death.
Cynthia is admonished by the Queen when she tries to fit the Queen's foot into the wrong shoe. Shoes made for the left foot and the right foot were not introduced in England until the 1860's.