The Knee fibula, a common design in the 2nd century AD, originated in Roman Pannonia (modern Hungary). With its short, fat bow that incorporates a 90 degree bend, archeologists thought it resembled a knee and leg. Many Knee fibulae have small rectangular, or larger semi-circular head plates. Knee fibulae appear, like the Augen type, to have been introduced into the Roman Empire by Germanic allies. Despite their small size, their appearance in Roman military graves implies that the Knee fibula was the most popular fibula among Roman soldiers in the 2nd century AD. They are rarely found outside military sites or contexts.