Brooches were used as practical accessories to help keep cloaks, trousers and other pieces of clothing fastened. The accessories were status symbols with many brooches being made of expensive materials. The more elaborate the deign also indicated the status of the wearer. These kinds of zoomorphic brooches were commonly found in Roman providences with the inspiration coming from British styles. The horse within Roman design is thought to be one of the animals to represent the Roman Empire as the animal was essential to the Roman military. The horse was a regularly used emblem in art, thought to be a symbol of victory, power and pride.
For more information on ancient Roman animal symbolism, please see our blog post: Animal Symbolism in Roman Art