Isis
Isis was originally worshipped by the ancient Egyptians and brought to Italy in the first century BC via the port cities such as Neapolis, Pozzuli, and Pompeii.
The temple of Isis in Pompeii is well known first as being one of the oldest sites of her worship in Italy and the fact that it was rededicated by Popidius in order to put his six year old son on the decurion council. Isis was a popular deity worshipped across the social classes of Roman society and reached to Roman Britain via the army and merchants though no altars survive in Great Britain.
Isis was a mother goddess and has been equated with numerous other deities including Minerva and Juno. During the Roman occupation of Egypt she was the foremost worshipped deity and this was the main reason she spread throughout the Roman Empire. Isis continued to be worshipped until the 6th century AD and competed with Christianity. We know most of our information about Isis from the Roman author Apuleius, a devote follower of the goddess who wrote the Golden Ass and described the worship of Isis in Italy.