A fibula (/ˈfɪbjʊlə/, plural fibulae /ˈfɪbjʊli/) is a brooch or pin for fastening garments, typically at the right shoulder. The fibula developed in a variety of shapes, but all were based on the safety-pin principle. Unlike most modern brooches, fibulae were not only decorative; they originally served a practical function: to fasten clothing for both sexes, such as dresses and cloaks. In English, "fibula" is not a word used for modern jewellery, but by archaeologists, who also use "brooch", especially for types other than the ancient "safety pin" types, and for types from the British Isles.
There are hundreds of different types of fibulae. They are usually divided into families that are based upon historical periods, geography, and/or cultures. Fibulae are also divided into classes that are based upon their general forms. Fibulae replaced straight pins that were used to fasten clothing in the Neolithic period and the Bronze Age. In turn, fibulae were replaced as clothing fasteners by buttons in the Middle Ages. Their descendant, the modern safety pin, remains in use today.
In ancient Rome and other places where Latin was used, the same word denoted both a brooch and the fibula bone because a popular form for brooches and the shape of the bone were thought to resemble one another. Some fibulae were also sometimes used as votive gifts for gods.
Lost fibulae, usually fragments, are frequently dug up by amateur coin and relic hunters using metal detectors.
Most fibulae are made of bronze (more properly "copper alloy") or iron, or both. Some fibulae are made of precious metals such as silver or gold. Most fibulae are made of only one or two pieces. Many fibulae are decorated with enamel, semi-precious stones, glass, coral or bone.
Fibulae were composed of four components: the body, pin, spring, and hinge.
The body of a fibula is known as either the bow or the plate, depending on the basic form. A bow is generally long and narrow, and often arched. A plate is flat and wide. Plates could be solid or openwork.