Long before the advent of quartz crystals, digital displays, or GPS-enabled smartphones, ancient Romans were already walking around with personal time-telling devices in their hands. We are not talking about watches in the modern sense, of course, yet they fulfilled a strikingly similar role: they offered information, gave their wearer a certain sophistication, and served as portable links to the wider world.

Compact, elegant, and surprisingly complex, Roman portable sundials were the ultimate accessory for the early-tech adopters of antiquity. These handheld gadgets became popular — or viral, if we want to use contemporary lingo —  during the late Roman Empire, mostly from the 2nd to 4th centuries AD.