The Tiffany Problem, or Tiffany Effect, refers to the issue where a historical or realistic fact seems anachronistic or unrealistic to modern audiences of historical fiction, despite being accurate. This often occurs with names, terms, or practices that, although historically accurate, feel out of place because of modern associations.^[1]

Author Nicola Cornick first discussed the Tiffany Effect in 2018 after learning about the phenomenon and encountering the term. She explained that the name Tiffany derives from Theophania, a name for girls in medieval England and France. The old French form c. 1200 was Tifinie, and the spelling Tiffany first appears in English c. 1600.^[2] However, if a historical fiction writer were to name an English character Tiffany in an Early Modern European setting as early as 1600, the audience would likely perceive it as inaccurate, associating the name with contemporary times or the 1980s in particular when the name reached peak popularity.^[3] Fellow author Jo Walton coined the term Tiffany Problem in 2019 to refer to this phenomenon.^[4]

Like the name Tiffany, the following names have been mistakenly thought to be of modern origin but are actually historical:

• Shane, which dates back to the 17th century as a masculine name derived from Gaelic
• Beverly, which originated from the term "beaver meadow" and has historical usage
• Wade, which is rooted in Early English and was popular in the medieval period
• Nicola, which was historically used as a male name in Italy and was borne by notable figures like the 12th-century Nicola de la Haye^[2]

The first known vending machine, created in the 1st century A.D. by Hero of Alexandria, dispensed holy water. This invention predates the modern concept of vending machines by nearly 2,000 years, making it seem anachronistic in ancient history.^[5]

Another example is the hoodie in the form of a woollen or cotton pullover with a hood; although most people likely believe it to be a late 20th-century garment, its existence dates back to much earlier. One form of it is, in the form of the garnache, a hooded tunic worn in foul weather throughout the Middle Ages in Europe and Egypt. The earliest surviving European example is the Bernuthsfeld Tunic from the Hogehahn bog in Lower Saxony, Germany and has been dated to the late 7th or early 8th century CE. Another example, dated to the 13th century, is a silk-gauze christening garment found in Prague Castle. Garnaches appear in numerous medieval manuscripts from the early through the late Middle Ages. Hooded tunics were also quite popular for children in Egypt and many examples survive from the 7th to 12th centuries CE when Egypt was under Islamic rule.

European royalty would have worn silk long before sericulture was brought from China in 552 CE, when two monks, charged by Emperor Justinian, successfully smuggled silkworm larvae from China back to Byzantium, which broke the Chinese monopoly on silk outside of Eastern Asia. The Silk Road connected China with Europe as early as the first century BC, making silk garments and textiles a fixture of the elite for many hundreds of years.^[6]

The oldest recognizably modern postal service (using riders and coaches) can be traced back to the first century in Rome (cursus publicus), and these systems existed at least until the 6th century with some breaks in the 3rd century, continuing in some parts of Europe, on and off, until the 18th century (Kaiserliche Reichspost). The Inca Empire also had an extensive postal system, which was facilitated by more than 15,000 miles (24100 km) of roads. A system of runners could allegedly deliver messages from one end of the empire to the other in under a week, covering a distance of nearly 2000 miles (3200km).

• Anachronism
• Historical authenticity
• Suspension of disbelief
• Verisimilitude

• Walton, Jo (2019-05-21). "Putting the Historical in Historical Fantasy". Tor/Forge Blog.