This group of minor deities originated in Greek lore. Little is known about them, although their name is believed to have Semitic roots. It's believed that they bear a connection to the sea, and offered protection to sailors and ships. Originally, there were only two Cabiri, the elder one identified with Dionysus and the younger with Hermes. In the early days of their worship they were grouped with Demeter and Ceres, and they eventually split into two sets.
A festival was held every year in Lemnos in honour of the deities. The festival lasted for nine days and saw all fires extinguished and sacred fire instead delivered from Delos. This has led some to believe the Cabiri to be demons of volcanos.
The Cabiri are often depicted as magicians with great power, and they have been described as the sons of Vulcan. Cicero, however, viewed the deities as the children of Prosperine, with their father being Jupiter. It's likely that the Cabiri originated in Semitic beliefs, although the temple of Memphis is consecrated to them in Egypt. Herodotus noted that the cult may have started with the Pelasgians, who took mysteries from the island of Samothrace to Athens.